Question

what is the time period for which rupees 8000 amount to rupees 12000 at 20 per annum of simple interest

Answer 1

Amount = 12000 Rs

Principal = 8000 Rs

SI = Amount - Principal = 12000-8000= 4000

Principal = 8000

SI = 4000

Rate = 20%

Time = (SI×100)/(Principal×Rate)

=(4000×100)/(8000×20)

=400000/160000

= 2.5. Years or 2 and ½ years.

Answer 2

In 2.5 years  8000 amounts to 12000 at the rate of 20% per annum

Given:

• P = 8000           ( P + principal)
• A = 12000         (A = Amount)
• R = 20 % per annum  ( R = Rate of Interest)

To Find:

• Time period

Solution:

• SI = P × R × T /100        ( SI = Simple Interest)
• SI = A - P

Step 1:

Calculate Simple  interest (SI)

SI = A - P

SI = 12000 - 8000

SI = 4000

Step 2:

Use formula  for simple interest and substitute the values

SI = P × R × T /100

4000 = 8000   × 20 × T /100

Step 3:

Solve for T:

4000 = 80   × 20 × T  

=> 200 = 80 × T

=> 20 = 8T

=> T = 20/8

=> T = 2.5

In 2.5 years  8000 amounts to 12000 at the rate of 20% per annum