Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
Prices of foodgrains have risen by 10\% and of other items of consumption by 15\%. If the ratio of an employee's expenditure on foodgrains and other items is 2 : 5, by how much should his salary be increased so that he may maintain the same level of consumption as before, assuming that his present salary is ₹ 3500?
(a)₹ 300
(b)₹ 350
(c)₹ 375
(d)₹ 475
Answer
Answer (as printed): D
Explanation
Let the man's original expenditure on foodgrains and other items be ₹ $2 x$ and ₹ $5 x$ respectively. Then, total original expenditure $=₹(2 x+5 x)=₹ 7 x$. Total new expenditure $=₹(110 \%$ of $2 x+115 \%$ of $5 x)$ $$\begin{aligned} & =₹\left(\frac{110}{100} \times 2 x+\frac{115}{100} \times 5 x\right)=₹\left(\frac{11 x}{5}+\frac{23 x}{4}\right) \\ & =₹\left(\frac{159 x}{20}\right) . \end{aligned}$$ Ratio of increased expenditure to original expenditure $$=\frac{159 x}{20} \times \frac{1}{7 x}=\frac{159}{140} .$$ ∴ Required salary $=₹\left(\frac{159}{140} \times 3500\right)=₹ 3975$. Desired increase in salary $=₹(3975-3500)=₹ 475$.
Explanation as extracted from the printed page; notation may be imperfect.