Mar 24, 2022

# Simple interest

## where P = Principal,

R = Rate of Interest in % per year/ annum,

T = Time, in years.

The rate of interest is in percentage r% and is to be written as r/100. (Simple and Compound Interest)

Find the simple interest, when:

Q) Principal = Rs 1000, Rate of Interest = 5% per annum and Time = 5 years.

solution:

Principal (P) = Rs 1000
Rate of interest (R) = 5% p.a.
Time (T) = 5 years
S.I. =( P × R × T)/100=

=(1000×5×5)/100

SI=250 rs

Q) Principal = Rs 1000, Rate of Interest = 10% per annum and Time = 73 days.

solution:

Principal (P) = Rs 1000
Rate of interest (R) = 10% p.a.
Time (T) = 73 days = 73365 year (1 year = 365 days)

Simple interest = P×R×T100=1000×10×73100×365=Rs 20

(Simple and Compound Interest)

Q) Principal = Rs 1000, Rate of Interest = 12.5% per annum and Time = 4 years.

solution:

Principal (P) = Rs 1000
Rate of interest (R) = 12.5% p.a.
Time (T) = 4 years
S.I. =( P × R × T)/100

= 1000×12.5×4100

SI=500Rs

Q) Principal = Rs 4500, Rate of Interest = 4% per annum and Time =12 months.

solution:

Principal (P) = Rs 4500
Rate of interest (R) = 4% p.a.
Time (T) = 12 months

T =1 year
S.I. =( P × R × T)/100

=Rs180

Q)Principal = Rs 12000, Rate of Interest = 18% per annum and Time = 4 months.

solution:

Principal (P) = Rs 12000
Rate of interest (R) = 18% p.a.
Time (T) = 4 months =412=13year (1 year = 12 months)

S.I. =( P × R × T)/100

=Rs 720

Q) Amit  pays Rs 9000 as an amount on the sum of Rs 7000 that he had borrowed for 2 years. Find the rate of interest.

Solution:

A = Rs 9000

P = Rs 7000

SI = A – P = 9000 – 7000 = Rs 2000

T = 2 years

R = ?

SI = (P × R ×T) / 100

R = (SI × 100) /(P× T)

R = (2000 × 100 /7000 × 2) =14.29 %

so,

R = 14.29%

All Job’s

You Tube

Practice Questions
Q)A sum fetched a total simple interest of Rs. 4016.25 at the rate of 18% per annum in 10 years. What is the sum?

Q)A sum of Rs. 725 is lent at the beginning of a year at a specific rate of interest. After eight months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both loans. What was the actual rate of interest?

Q)Simple interest on a certain sum is 16/25 of the sum. Find the rate of interest and time if both are numerically equal.

Q)How long will Rs. 1500 take to yield a simple interest of Rs.90 at11% per annum?