Q. |
The price of petrol increases by 30%, a man reduces consumption by such a percent so that his expenditure can only go up by 10%. By what % does he decrease his consumption? |
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A. 20% |
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B. 17% |
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C. 43% |
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D. 15.38% |
Apply AB Method.
In this question decrease, the percentage of consumption is asked. Let’s take it ‘x’
30 – x – 30*x / 100 = 10
– 13x/10 = – 20
X = 200/13
x = 15.38 %
Note: To solve these kinds of questions where either A or B (of AB method) is asked, you can use the hit and trial (Options elimination process) method to get the answer.
Ex. If we apply the first option i.e. 20%,
30 - 20 - 30*20/100 = 4% (net result must be 10. hence eliminated)
Similarly, other options can be applied.