Question

A sum of money lent on simple interest becomes 7 by 5 of itself in 4 years .Find the rate of interest per annum​

Answer 1

Given:-

• A sum of money lent on simple interest becomes 7/5.
• The time taken is 4 years.

To Find:-

• Find the Rate of Interest per annum.

Solution:-

⟹ Let the Principal be 100.

➣ Amount = 7/5 × P

➣ Amount = 7/5 × 100

➣ Amount = 700/5

➣ Amount = 140

Now,

➣ Simple Interest = Amount - Principal

➣ Simple Interest = 140 - 100

➣ Simple Interest = 40

Now,

Rate of Interest =

➣ S.I = PTR/100

➣ 40 = 100 × 4 × R/100

➣ 40 = 4R

➣ R = 40/4

$\boxed{\bf{\color{ellow}{ \: Rate \: \: of \: \: Interest \: \: = \: \: 10 \: }}}$

More to know:-

➣ Profit = SP - CP

➣ Loss = CP - SP

➣ Discount = MP - SP