A certain some amounts to ₹8,192 in 3 years and to ₹9,472 in 6 years, at simple interest at a certain rate percent p. a. The rate of interest, and the sum are ______and______, respectively.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 8%; ₹6,400.
SI = (P×R×T)/100
time difference between 6 years and 3½ years = 6 − 3.5 = 2.5 years
Difference in amount = 9472−8192 = ₹1280
₹1280 is the simple interest for 2.5 years.
(P × R × 2.5)/100 = 1280
P × R = 51200
SI for 3.5 years = (P × R × 3.5)/100 = (51200 × 3.5)/100 = ₹1792
P = 8192 − 1792 = ₹6400
P × R = 51200 ⇒ 6400 × R = 51200
R = 51200/6400 = 8%