21. If Rs. 10 be allowed as true discount on bill of Rs. 110 due at the end of a certain time, then the discount allowedon the same sum due at the end of double the time is:
A. 16
B. 18.33
C. 20.21
D. 26
Answer: B.
Explanation:
S.I. on Rs. (110 - 10) for a certian time = Rs. 10.
S.I. on Rs. 100 for double the time = Rs. 20.
T.D. on Rs. 120 = Rs. (120 - 100) = Rs.20
T.D. on Rs. 110 = Rs. [20 /120 * 110] = Rs. 18.33
