The interest earned on ₹ 4000 when invested in Scheme A for two years at 7\% p.a. simple interest is half of the interest earned when ₹ 'X' is invested for five years in the same scheme at the same rateof interest. What is the value of X?
(a)2000
(b)2800
(c)3000
(d)3200
(e)3600
Answer
Answer (as printed): D
Explanation
Simple Interest earned in scheme A $=\frac{\text{P}\times \text{R}\times \text{T}}{100}=\frac{4000 \times 7 \times 2}{100}=₹560$. Interest earned in scheme B $=560 \times 2=₹1120$. Let 'A' be the principal amount invested in scheme B. Interest $=\frac{\text{Principal}\times \text{Rate}\times \text{Time}}{100} \Rightarrow 1120=\frac{A \times 7 \times 5}{100} \Rightarrow A=₹3200$.
Explanation as extracted from the printed page; notation may be imperfect.