Question

Find the sum which earned rs 1200 as simple interest in 5 years,

Rate of interest being 12 % p.a.

Answer 1

If P denotes the principal ($), R denotes the rate (percentage p.a.) and T denotes time (years), then:-

SI=simple interest

S.I = (P × R × T)/100

R = (S.I × 100)/(P × T)

P = (S.I × 100)/(R × T)

T = (S.I × 100)/(P × R)

If the denotes the amount, then A = P + S.I

R=12%
T=5years=5*12/12yr =60/12=5
P=1200
SI=(1200*5*12%)/100
SI =(1200*5*5)/100
=300rs
If the denotes the amount, then A = P + S.I
A =1200+300
=1500