NIMCET 2025
If a number is increased by 30% and then decreased by 20%, what is the net change?
Answer (Detailed Solution Below)View answer ▾Hide ▴
Answer: Option D — 4% increase
Detailed Solution
, so the net change is a 4 percent increase.
✓ Check
100 becomes 130, then .⚠ Common trap
Subtracting the rates ( ) ignores that the 20 percent is taken on 130, not on 100.Quick tip
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Ask a doubtMore Percentage Questions
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Percentage — Preparation
This question tests your understanding of Percentage, a key topic in the Quantitative Aptitude section. The detailed solution above uses a step-by-step approach to show the reasoning, and where available, a shortcut that helps you solve similar questions in under 90 seconds during the actual exam.
A percentage expresses a number as a fraction of 100. It is one of the most important topics in quantitative aptitude because profit and loss, simple and compound interest, data interpretation and many word problems are built on it. Questions test percentage increase and decrease, successive percentage changes, the effect of a price change on consumption or expenditure, population growth, election and examination results, and comparisons such as "by what percent is A more than B". Learning fraction equivalents (1/6 = 16.67%, 1/7 = 14.28%, 1/9 = 11.11% and so on) lets you avoid long division. For two successive changes of a% and b%, the net change is a + b + ab/100, a formula that saves time in many questions. Work through the percentage questions below. Each one has a step-by-step solution and, where possible, a fraction-based shortcut.