₹ 20 is the true discount on ₹ 260 due after a certain time. What will be the true discount on the same sum due after half of the former time, the rate of interest being the same?
(a)₹ 10
(b)₹ 10.40
(c)₹ 15.20
(d)₹ 13
Answer
Answer (as printed): B
Explanation
S.I. on ₹ (260-20) for a given $\mathrm{time}=₹ 20$. S.I. on ₹ 240 for half the time $=₹ 10$. T.D. on ₹ $250=₹ 10$. $\therefore \quad$ T.D. on ₹ $260=₹\left(\frac{10}{250} \times 260\right)=₹ 10.40$.
Explanation as extracted from the printed page; notation may be imperfect.