Question

The C.I. at a certain rate for Rs. 'X' for 2
years is same as the S.l. at the same rate
for same Rs. 'X' for four years. Find the rate.
(in % per annum)
1) 200 2) 300 3) 400 4) 500 5) 250​

Answer 1

Answer:

1) 200

Step-by-step explanation:

CI = Compound Interest

SI = Simple Interest

P = Principal Amount, i.e, X in your case

i = rate/100

CI = P(1+i)^n - P

SI = Pin

P(1+i)^2 - P = P×i×4

P{(1+i)^2 - 1} = P × 4i

Dividing both sides by P,

(1+i)^2 - 1 = 4i

(1+i)^2 - 4i = 1

(1 + i^2 + 2i) - 4i = 1

i^2 - 2i= 1-1

i^2 = 2i

i = 2

rate/100 = 2

Hence, Rate = 200