Peter could save 10\% of his income. But two years later when his income is increased by 20\%, he could save the same amount only as before. By how much percent has his expenditure increased?
(a)22\%
(b)$22 \frac{2}{9} \%$
(c)$23 \frac{1}{3} \%$
(d)24\%
Answer
Answer (as printed): B
Explanation
Let original income = ₹ 100. Then, saving = ₹ 10 and expenditure $=₹ 90$. New income $=₹ 120$, New saving $=₹ 10$. New expenditure $=₹(120-10)=₹ 110$. Increase in expenditure $=₹(110-90)=₹ 20$. $$\text { ∴ Increase } \%=\left(\frac{20}{90} \times 100\right) \%=22 \frac{2}{9} \% \text {. }$$
Explanation as extracted from the printed page; notation may be imperfect.