Percentage Questions for Placements with Tricks

Percentage Questions for Placements with Tricks

Percentages are one of the highest-weightage topics in aptitude for placements. From salary hike calculations to population growth problems, percentages appear in dozens of forms across placement tests. Developing speed with percentages directly improves your overall aptitude score in every placement exam you attempt.

Core Concept

A percentage is a fraction with denominator 100. When you say 25 percent, you mean 25 out of every 100. Most placement problems require moving quickly between percentage, fraction, and decimal forms. Key conversions to memorize: one quarter equals 25 percent, one fifth equals 20 percent, one eighth equals 12.5 percent, and one third equals approximately 33.33 percent.

Successive Percentage Change

If a value changes by a percent and then by b percent, the net percentage change equals a plus b plus ab divided by 100. When one change is positive and the other negative — for example, a 20 percent increase followed by a 20 percent decrease — the net result is never zero. It is always a loss of a squared divided by 100 percent.

Solved Example

A salary is increased by 20 percent and then decreased by 20 percent. Net change equals 20 plus negative 20 plus 20 times negative 20 divided by 100. This simplifies to 0 minus 4, giving a net decrease of 4 percent. Verification with base 100: after 20 percent increase the value is 120, after 20 percent decrease it is 96. Net change is negative 4 percent.

Interview Tips

In placement tests, percentage questions often disguise themselves as data interpretation or profit-loss problems. Practice converting between percentages and fractions rapidly — this alone saves 30 to 40 seconds per question. The successive percentage change formula is a high-frequency shortcut that many candidates do not know, giving you a significant competitive edge over less prepared test-takers.