{"id":180258,"date":"2025-10-06T17:21:40","date_gmt":"2025-10-06T11:51:40","guid":{"rendered":"https:\/\/www.practicemock.com\/blog\/?p=180258"},"modified":"2025-10-06T17:28:38","modified_gmt":"2025-10-06T11:58:38","slug":"100-quant-shortcuts-for-ibps-rrb-clerk-exam-with-examples","status":"publish","type":"post","link":"https:\/\/www.practicemock.com\/blog\/100-quant-shortcuts-for-ibps-rrb-clerk-exam-with-examples\/","title":{"rendered":"100 Quant Shortcuts for IBPS RRB Clerk Exam with Examples"},"content":{"rendered":"\n

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Home<\/a><\/span> \u00bb IBPS RRB Clerk<\/a><\/span> \u00bb 100 Quant Shortcuts for IBPS RRB Clerk Exam with Examples<\/span><\/span><\/div>\n\n\n

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In the IBPS RRB Clerk Quant\/ Numerical Ability section, speed and accuracy are everything. With only 20 minutes to solve 40 questions, you can\u2019t afford long calculations. That\u2019s where shortcuts come in. Using them reduces time to calculate the answer to a question. When you learn and apply them in mock tests, your speed improves. Below, you\u2019ll find 100 powerful tricks across all arithmetic topics, each explained with an example so you can apply them in your tests and score well in the exam.<\/p>\n\n\n\n

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Take a Free RRB Clerk Mock Test<\/strong><\/a><\/div>\n<\/div>\n\n\n\n

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Topic-wise 100 Quant Arithmetic Shortcuts for RRB Clerk Exam<\/strong><\/h2>\n\n\n\n

Mastering topic\u2011wise 100 Quant Arithmetic shortcuts for the IBPS RRB Clerk exam is all about breaking down each chapter into its most efficient formulas and time\u2011saving tricks. From percentages, profit and loss, averages, and ages to more complex areas like simple and compound interest, mixture and alligation, time\u2013speed\u2013distance, time and work, and data interpretation, every topic has its own set of quick methods that cut calculation time drastically. For example, using the alligation rule in mixtures, successive percentage formulas for profit and loss, or LCM methods in time and work<\/strong> can help solve questions in seconds instead of minutes. Check topic-wise quant shortcuts with an example given below.<\/p>\n\n\n\n

Percentages (10 Shortcuts)<\/strong><\/h3>\n\n\n\n
    \n
  1. x% of y = y% of x
    <\/strong> Example: 25% of 200 = 200\u00d725\/100 = 50. Or 200% of 25 = 50.
    <\/li>\n\n\n\n
  2. Increase by x% then decrease by x% \u2192 Net change = \u2013(x\u00b2\/100)<\/strong>
    <\/strong> Example: Increase 100 by 20% \u2192 120. Then decrease by 20% \u2192 96. Net change = \u20134%. Formula: \u2013(20\u00b2\/100) = \u20134%.
    <\/li>\n\n\n\n
  3. Fraction to % conversions<\/strong>
    <\/strong> Example: 1\/8 = 12.5%, 3\/20 = 15%. Memorize common ones for speed.
    <\/li>\n\n\n\n
  4. Successive % change formula: A + B + (AB\/100)<\/strong>
    <\/strong> Example: Increase 20% then 10% \u2192 Net = 20+10+(20\u00d710\/100) = 32%.
    <\/li>\n\n\n\n
  5. % change = (Difference\/Base)\u00d7100<\/strong>
    <\/strong> Example: From 80 to 100 \u2192 (20\/80)\u00d7100 = 25%.
    <\/li>\n\n\n\n
  6. If A is x% more than B \u2192 B is (x\/(100+x))% less than A<\/strong>
    <\/strong> Example: A is 25% more than B \u2192 B is 25\/125 = 20% less than A.
    <\/li>\n\n\n\n
  7. If A is x% less than B \u2192 B is (x\/(100\u2013x))% more than A<\/strong>
    <\/strong> Example: A is 20% less than B \u2192 B is 20\/80 = 25% more than A.
    <\/li>\n\n\n\n
  8. Quick % mental math
    <\/strong>Example: 10% = \u00f710, 5% = \u00f720, 1% = \u00f7100. So 5% of 240 = 240\u00f720 = 12.
    Learn     1 to 100 percent to fraction conversion<\/a> from here.<\/li>\n\n\n\n
  9. Cancel zeros before multiplying<\/strong>
    <\/strong> Example: 25% of 2400 = (25\u00d724) = 600.
    <\/li>\n\n\n\n
  10. Approximation for DI<\/strong>
    <\/strong> Example: 19.8% of 499 \u2248 20% of 500 = 100.<\/li>\n<\/ol>\n\n\n\n

    Profit & Loss (8 Shortcuts)<\/strong><\/h3>\n\n\n\n
      \n
    1. Profit% = (Profit\/CP)\u00d7100<\/strong>
      <\/strong> Example: CP=100, SP=120 \u2192 Profit=20 \u2192 Profit%=20%.
      <\/li>\n\n\n\n
    2. SP = CP \u00d7 (100+Profit%)\/100<\/strong>
      <\/strong> Example: CP=500, Profit%=20 \u2192 SP=500\u00d7120\/100=600.
      <\/li>\n\n\n\n
    3. CP = SP \u00d7 100\/(100+Profit%)<\/strong>
      <\/strong> Example: SP=600, Profit%=20 \u2192 CP=600\u00d7100\/120=500.
      <\/li>\n\n\n\n
    4. Successive profit\/loss<\/strong>
      <\/strong> Example: 20% profit then 10% loss \u2192 Net=20\u201310+(20\u00d7\u201310\/100)=8% profit.
      <\/li>\n\n\n\n
    5. Discount% = (MRP\u2013SP)\/MRP\u00d7100<\/strong>
      <\/strong> Example: MRP=1000, SP=800 \u2192 Discount=20%.
      <\/li>\n\n\n\n
    6. Two successive discounts<\/strong>
      <\/strong> Example: 20% then 10% \u2192 Net=20+10\u2013(20\u00d710\/100)=28%.
      <\/li>\n\n\n\n
    7. Marked Price = SP\u00d7100\/(100\u2013Discount%)<\/strong>
      <\/strong> Example: SP=800, Discount=20% \u2192 MP=800\u00d7100\/80=1000.
      <\/li>\n\n\n\n
    8. Chain transactions<\/strong>
      <\/strong> Example: CP=100, Profit=20% \u2192 SP=120. Then sold at 10% loss \u2192 Final SP=108.<\/li>\n<\/ol>\n\n\n\n

      <\/p>\n\n\n

      \n
      \"banking<\/a><\/figure><\/div>\n\n\n

      <\/p>\n\n\n\n

      Partnership (5 Shortcuts)<\/strong><\/h3>\n\n\n\n
        \n
      1. Profit share \u221d Investment\u00d7Time<\/strong>
        <\/strong> Example: A invests 6000 for 12 months, B invests 9000 for 8 months \u2192 Ratio=72000:72000=1:1.
        <\/li>\n\n\n\n
      2. Adjust for time<\/strong>
        <\/strong> Example: A invests 5000 for 12 months, B invests 5000 for 6 months \u2192 Ratio=5000\u00d712:5000\u00d76=2:1.
        <\/li>\n\n\n\n
      3. Sleeping partner<\/strong>
        <\/strong> Example: If C invests nothing, his share=0.
        <\/li>\n\n\n\n
      4. Back\u2011calculate investments<\/strong>
        <\/strong> Example: Profit ratio=2:3, Time same \u2192 Investment ratio=2:3.
        <\/li>\n\n\n\n
      5. Multiple partners<\/strong>
        <\/strong> Example: A=6000\u00d712, B=9000\u00d78, C=12000\u00d76 \u2192 Ratio=72000:72000:72000=1:1:1.<\/li>\n<\/ol>\n\n\n\n

        You can also look at the quant formulas and concepts<\/a> well explained here!<\/p>\n\n\n\n

        Ages (5 Shortcuts)<\/strong><\/h3>\n\n\n\n
          \n
        1. Use algebra<\/strong>
          <\/strong> Example: Father=4x, Son=x. After 5 years: (4x+5)\/(x+5)=3 \u2192 Solve.
          <\/li>\n\n\n\n
        2. After n years = x+n<\/strong>
          <\/strong> Example: Son=10, after 5 years=15.
          <\/li>\n\n\n\n
        3. Difference constant<\/strong>
          <\/strong> Example: Father=40, Son=10 \u2192 Difference=30 always.
          <\/li>\n\n\n\n
        4. Average age<\/strong>
          <\/strong> Example: 5 persons, avg=20 \u2192 Total=100.
          <\/li>\n\n\n\n
        5. Replacement<\/strong>
          <\/strong> Example: Avg=20, one leaves (25), new avg=19 \u2192 New person=14.<\/li>\n<\/ol>\n\n\n\n

          Averages (6 Shortcuts)<\/strong><\/h3>\n\n\n\n
            \n
          1. Average=Sum\/Number<\/strong>
            <\/strong> Example: (10+20+30)\/3=20.
            <\/li>\n\n\n\n
          2. New average<\/strong>
            <\/strong> Example: Old avg=20, 5 numbers=100. Add 30 \u2192 New avg=(130\/6)=21.67.
            <\/li>\n\n\n\n
          3. Weighted average<\/strong>
            <\/strong> Example: 2 students avg=20, 3 students avg=30 \u2192 Weighted avg=(2\u00d720+3\u00d730)\/5=26.
            <\/li>\n\n\n\n
          4. Replacement formula<\/strong>
            <\/strong> Example: Old avg=20, replaced 25 with 30 \u2192 New avg=20+(30\u201325)\/n.
            <\/li>\n\n\n\n
          5. Consecutive numbers<\/strong>
            <\/strong> Example: 1 to 9 \u2192 Avg=5.
            <\/li>\n\n\n\n
          6. Even consecutive<\/strong>
            <\/strong> Example: 2,4,6,8 \u2192 Avg=(2+8)\/2=5.<\/li>\n<\/ol>\n\n\n\n

            Simple & Compound Interest (10 Shortcuts)<\/strong><\/h3>\n\n\n\n
              \n
            1. SI=(P\u00d7R\u00d7T)\/100<\/strong>
              <\/strong> Example: 1000 at 10% for 2 yrs=200.
              <\/li>\n\n\n\n
            2. Amount=P+SI<\/strong>
              <\/strong> Example: 1000+200=1200.
              <\/li>\n\n\n\n
            3. CI=P[(1+R\/100)^T\u20131]<\/strong>
              <\/strong> Example: 1000 at 10% for 2 yrs=1000\u00d7(1.21\u20131)=210.
              <\/li>\n\n\n\n
            4. Difference CI\u2013SI (2 yrs)=P\u00d7(R\u00b2\/100\u00b2)<\/strong>
              <\/strong> Example: 1000 at 10% \u2192 1000\u00d70.01=10.
              <\/li>\n\n\n\n
            5. For 3 yrs<\/strong>
              <\/strong> Example: Formula extension.
              <\/li>\n\n\n\n
            6. Half\u2011yearly CI<\/strong>
              <\/strong> Example: 1000 at 10% for 1 yr \u2192 R=5%, T=2 \u2192 CI=1000\u00d7(1.05\u00b2\u20131)=102.5.
              <\/li>\n\n\n\n
            7. Quarterly CI<\/strong>
              <\/strong> Example: 1000 at 12% for 1 yr \u2192 R=3%, T=4 \u2192 CI=1000\u00d7(1.03\u2074\u20131)=125.5.
              <\/li>\n\n\n\n
            8. Rule of 72<\/strong>
              <\/strong> Example: At 12% \u2192 Double in 72\/12=6 yrs.
              <\/li>\n\n\n\n
            9. Rule of 69<\/strong>
              <\/strong> Example: At 10% \u2192 Double in 69\/10\u22487 yrs.
              <\/li>\n\n\n\n
            10. Recurring deposits<\/strong>
              <\/strong> Example: Use AP formula.<\/li>\n<\/ol>\n\n\n\n

              Mixture & Allegation (5 Shortcuts)<\/strong><\/h3>\n\n\n\n

              45. Mean Price Formula<\/strong>
              <\/strong> Mean Price = (Qty\u2081\u00d7Price\u2081 + Qty\u2082\u00d7Price\u2082)\/(Qty\u2081+Qty\u2082)
              Example:<\/em> 2 kg rice at \u20b950\/kg and 3 kg at \u20b960\/kg \u2192 Mean = (100+180)\/5 = \u20b956\/kg.<\/p>\n\n\n\n

              46. Rule of Allegation (Shortcut Ratio)<\/strong>
              <\/strong> Ratio = (High\u2013Mean):(Mean\u2013Low)
              Example:<\/em> Mix milk at \u20b96\/litre and water at \u20b92\/litre to sell at \u20b94\/litre \u2192 Ratio = (6\u20134):(4\u20132) = 2:2 = 1:1.<\/p>\n\n\n\n

              47. Milk\u2013Water Problems<\/strong>
              <\/strong> Example:<\/em> If 1 litre water is added to 4 litres milk, ratio = 4:1.<\/p>\n\n\n\n

              48. Replacement Formula<\/strong>
              <\/strong> Final concentration = Initial \u00d7 (1\u2013x\/n)^k
              Example:<\/em> 100 litres milk, 10 litres replaced with water, repeated twice \u2192 Final milk = 100\u00d7(1\u201310\/100)\u00b2 = 81 litres.<\/p>\n\n\n\n

              49. Successive Mixtures<\/strong>
              <\/strong> Apply allegation step by step for each mixing.<\/p>\n\n\n\n

              50. Shortcut Tip<\/strong>
              <\/strong> Always subtract diagonally in allegation to avoid confusion.<\/p>\n\n\n\n

              Ratio & Proportion (5 Shortcuts)<\/h3>\n\n\n\n

              51. Chain Ratios<\/strong>
              <\/strong> If a:b and b:c \u2192 a:b:c.
              Example:<\/em> a:b=2:3, b:c=4:5 \u2192 a:b:c=8:12:15.<\/p>\n\n\n\n

              52. Inverse Ratio<\/strong>
              <\/strong> If work is inversely proportional to time.
              Example:<\/em> A:B=2:3 in efficiency \u2192 Time ratio=3:2.<\/p>\n\n\n\n

              53. Direct Proportion<\/strong>
              <\/strong> a\u2081\/b\u2081=a\u2082\/b\u2082.
              Example:<\/em> 2 pens cost \u20b910, 5 pens cost x \u2192 x=25.<\/p>\n\n\n\n

              54. Compound Ratio<\/strong>
              <\/strong> Multiply ratios term\u2011wise.
              Example:<\/em> (2:3)\u00d7(4:5)=8:15.<\/p>\n\n\n\n

              55. Distribution<\/strong>
              <\/strong> Total \u00d7 (Ratio part\/Total ratio).
              Example:<\/em> \u20b9600 divided in 2:3 \u2192 A=600\u00d72\/5=240, B=360.<\/p>\n\n\n\n

              Time, Speed & Distance (10 Shortcuts)<\/strong><\/h3>\n\n\n\n

              56. Speed=Distance\/Time<\/strong>
              <\/strong> 120 km in 2 hrs \u2192 60 km\/h.<\/p>\n\n\n\n

              57. Time=Distance\/Speed<\/strong>
              <\/strong> 120 km at 60 km\/h \u2192 2 hrs.<\/p>\n\n\n\n

              58. Distance=Speed\u00d7Time<\/strong>
              <\/strong> 60 km\/h \u00d7 2 hrs=120 km.<\/p>\n\n\n\n

              59. Time \u221d 1\/Speed<\/strong>
              <\/strong> If speed doubles, time halves.<\/p>\n\n\n\n

              60. Relative Speed (Opposite)<\/strong>
              <\/strong> u+v.
              Example:<\/em> 60 & 40 km\/h opposite \u2192 100 km\/h.<\/p>\n\n\n\n

              61. Relative Speed (Same)<\/strong>
              <\/strong> u\u2013v.
              Example:<\/em> 60 & 40 km\/h same \u2192 20 km\/h.<\/p>\n\n\n\n

              62. Average Speed Formula<\/strong>
              <\/strong> 2xy\/(x+y).
              Example:<\/em> 60 km\/h one way, 40 km\/h return \u2192 Avg=48 km\/h.<\/p>\n\n\n\n

              63. Distance Same \u2192 Speed Ratio = Inverse Time Ratio<\/strong>
              <\/strong> Example:<\/em> Time ratio 2:3 \u2192 Speed ratio 3:2.<\/p>\n\n\n\n

              64. Time Same \u2192 Distance Ratio = Speed Ratio<\/strong>
              <\/strong> Example:<\/em> Speed ratio 2:3 \u2192 Distance ratio 2:3.<\/p>\n\n\n\n

              65. Train Crossing<\/strong>
              <\/strong> Time=Length\/Speed.
              Example:<\/em> Train 120m, speed 60 km\/h=16.67 m\/s \u2192 Time=120\/16.67\u22487.2s.<\/p>\n\n\n\n

              Time & Work (8 Shortcuts)<\/strong><\/h3>\n\n\n\n

              66. Work=Time\u00d7Efficiency<\/strong><\/p>\n\n\n\n

              67. Efficiency=1\/Days<\/strong>
              <\/strong> A completes in 10 days \u2192 Efficiency=1\/10.<\/p>\n\n\n\n

              68. Combined Work=Sum of Efficiencies<\/strong>
              <\/strong> A=1\/10, B=1\/20 \u2192 Together=3\/20 \u2192 20\/3 days.<\/p>\n\n\n\n

              69. Efficiency Ratio \u2192 Time Ratio<\/strong>
              <\/strong> If A:B efficiency=2:3 \u2192 Time ratio=3:2.<\/p>\n\n\n\n

              70. LCM Method<\/strong>
              <\/strong> Take total work=LCM of days.
              Example:<\/em> A=10 days, B=20 days \u2192 LCM=20 units.<\/p>\n\n\n\n

              71. Alternate Days<\/strong>
              <\/strong> Calculate 2\u2011day cycle.
              Example:<\/em> A=1\/2, B=1\/3 \u2192 2\u2011day work=5\/6.<\/p>\n\n\n\n

              72. Pipes & Cisterns<\/strong>
              <\/strong> Inlet=+ve, Outlet=\u2013ve.<\/p>\n\n\n\n

              73. Net Work=Sum of Rates<\/strong>
              <\/strong> A=1\/6, B=1\/4, C=\u20131\/12 \u2192 Net=1\/6+1\/4\u20131\/12=1\/3.<\/p>\n\n\n\n

              Boats & Streams (4 Shortcuts)<\/strong><\/h3>\n\n\n\n

              74. Downstream=u+v<\/strong>
              <\/strong> Boat=10, Stream=2 \u2192 12.<\/p>\n\n\n\n

              75. Upstream=u\u2013v<\/strong>
              <\/strong> Boat=10, Stream=2 \u2192 8.<\/p>\n\n\n\n

              76. Time=Distance\/Speed<\/strong><\/p>\n\n\n\n

              77. Boat Speed Formula<\/strong>
              <\/strong> d downstream in t\u2081, upstream in t\u2082 \u2192 Boat speed=d(1\/t\u2081+1\/t\u2082)\/2.<\/p>\n\n\n\n

              78. Stream Speed Formula<\/strong>
              <\/strong> d downstream in t\u2081, upstream in t\u2082 \u2192 Stream speed=d(1\/t\u2081\u20131\/t\u2082)\/2.<\/p>\n\n\n\n

              DI Shortcuts (10 Shortcuts)<\/strong><\/h2>\n\n\n\n

              79. Approximate values<\/strong><\/h3>\n\n\n\n