The salary of a worker is first increased by 30% and afterwards reduced by 30%. What is net change in his salary?
Correct answer: C. 9% decrease
- A. 90% increase
- B. 45% increase
- C. 9% decrease
- D. Same as before
Explanation
Take the original salary as 100%. After a 30% increase it becomes 130%, and reducing this new salary by 30% gives 130% x 70% = 91%. The final salary is therefore 9% lower than the original. The likely trap is choosing “same as before” by incorrectly cancelling the equal 30% increase and decrease, although the second percentage applies to a different base.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Percentages
Percentages express a quantity as parts per hundred and support calculations involving increases, decreases, discounts, commissions, taxes, and successive changes. Questions require distinguishing percentage change from percentage points and identifying the original value when a final value and its percentage change are given.
Practise Arithmetic
1,060 free Arithmetic MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Mathematics questions like this
Mathematics is on 76 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Percentages questions
In an examination, 47% failed in English and 54% failed in Mathematics. Find the pass percentage in both the subjects if 31% failed in both the subjects?
A person spends 1/5th of his income on the education of his children, and 20% of the remaining on food. If he is left with Rs.576 find his income?
In a school of 850 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
In an examination 40% failed in Urdu, 45% failed in English. If 25% students failed in both the subjects. Then the percentage of failed students is________?
After 38 liters of petrol were poured into the tank, it was still 5% empty. How much petrol must be poured into the tank in order to fill it?
A candidate who gets 30% of the marks fails by 50 marks. But another candidate who gets 45% marks gets 25 marks more than necessary for passing. Find the number of marks for passing?