Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
A man spends 75% of his income. If his income increases by 20% and his expenditure increases by 10%, what is the percentage increase in his savings?
40%
50%
60%
75%
50%
Assume Income = 100. Then Expenditure = 75 and Savings = 25. Apply percentage changes to these base values to find the new savings instantly.
Initial expenditure is 75% of income, income increases by 20%, and expenditure increases by 10%.
Income=Expenditure+Savings
Assume Income = 100. Then Expenditure = 75 and Savings = 25. Apply percentage changes to these base values to find the new savings instantly.
Students often calculate the percentage increase based on the original income (100) instead of the original savings (25), leading to incorrect answers like 15% instead of 50%.
Define Initial Values
Assume the initial income is 100. Since the expenditure is 75% of the income, Expenditure = 75. Therefore, Savings = Income - Expenditure = 100 - 75 = 25.
SinitialтАЛ=100тИТ75=25
Calculate New Values
The income increases by 20%, so New Income = 100 + 20% of 100 = 120. The expenditure increases by 10%, so New Expenditure = 75 + 10% of 75 = 75 + 7.5 = 82.5.
InewтАЛ=120,EnewтАЛ=82.5
Calculate New Savings and Increase
New Savings = New Income - New Expenditure = 120 - 82.5 = 37.5. The increase in savings is 37.5 - 25 = 12.5.
SnewтАЛ=37.5,╬ФS=12.5
Calculate Percentage Increase
The percentage increase in savings is (Increase in savings / Original savings) * 100 = (12.5 / 25) * 100 = 50%.
2512.5тАЛ├Ч100=50%
B is correct because the savings increase from 25 to 37.5, which is a 50% increase.
This logic is identical to mixture and allegation problems where you track the change in individual components relative to their base quantities.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants