A saves 35% of his income. If his income increases by 20.1% and his expenditure increases by 20%, then by what percentage do his savings increase or decrease? (correct to one decimal place)
(a) 19.75% of decrease
(b) 20.3% of increase
(c) 18.5% of decrease
(d) 21.9% of increase
{Previously asked in SSC CGL MAINS 2020}

Ans: (b) 20.3% of increase

Explanation:

Savings increases from 35 to 42.1

∴ % increase = \displaystyle\frac{7.1}{35}\times 100

\qquad\qquad = \displaystyle\frac{710}{35}

\qquad\qquad = \displaystyle\frac{142}{7}

\qquad\qquad = 20.3%