Question

SBI Clerk Prelims [2020) - 2
emailoftamil
Question: 48/100 Report
Numerical Ability
The ratio of the compound interest and the simple interest earned on the same principal when invested for 2 years at the same rate of interest per annum is 59 50. What is the rate of
interest?​

Answer 1

Answer:

Rate of interest = 36%

Step-by-step explanation:

C.I = P [ ( 1 + R / 100 )^n -1 ]

= P [ ( 1 + 0,01 R )^2 - 1 ]. ( R / 100 = 0.01 R)

( 1 + 0.01 R)^2 = 1 + 0.02R + 0.0001 R^2

C.I = P ( 1 + 0.02 R + 0.0001 R - 1 )

C.I = P ( 0.02 R + 0.0001 R^2)

C.I = P × R ( 0.02 + 0.0001 R)

S.I = ( P × R× T ) / 100

Given,

C.I / S.I. = 59 / 50 i.e

P × R × ( 0.02 + 0.0001 R ) ÷ (P × R×T) / 100 =59/50

( 0.02 + 0.0001 R) × 100 ÷ T = 59 / 50

( 2 + 0.01 R) / 2 = 59 / 50. ( T = 2 year)

50 ( 2 + 0.01 R) = 59 × 2. ( by cross multiplying)

100 + 0.5 R = 118

0.5 R = 118 - 100

0.5 R = 18

R. = 18 / 0.5

R = 36%