The rates of simple interest in two banks A and B are in the ratio 5 : 4. A person wants to deposit his total savings in two banks in such a way that he received equal half-yearly interest from both. He should deposit the savings in banks A and B in the ratio:
(a)2 : 5
(b)4 : 5
(c)5 : 2
(d)5 : 4
Answer
Answer (as printed): B
Explanation
Let the savings be $X$ and $Y$ and the rates of simple interest be $5 x$ and $4 x$ respectively. Then, $X \times 5 x \times \frac{1}{2} \times \frac{1}{100}=Y \times 4 x \times \frac{1}{2} \times \frac{1}{100}$ $$\text { or } \frac{X}{Y}=\frac{4}{5} \text {, i.e., } X: Y=4: 5 \text {. }$$
Explanation as extracted from the printed page; notation may be imperfect.