Question

What sum of money will amount to 3900 in 4 years at the rate of 7.5% per annum?​

Answer 1

Answer:

let the sum is Rs x

then ,

x+ x.4.7.5/100=3900

=> x+30x/100=3900

=> 130x=3900×100

=> x=3900×100/130

=> x=30×100

=> x=3000

the sum of money is Rs 3000

Answer 2

Principal = Rs. 3900

Rate = 7.5%

Time = 4 years

What to find?

We have to find the amount.

To find the amount we will have to find the simple interest using the formula SI=\frac{PRT}{100}SI=100PRT 

and

then find the amount using the formula A=SI+PA=SI+P .

Solution:

Using the formula,

⇒ SI=\frac{PRT}{100}SI=100PRT

Substitute the values,

⇒ SI=\frac{3900*7.5*4}{100}SI

=1003900∗7.5∗4

Cancel zeros in 3900 and 100

⇒ SI = 39 × 7.5 × 4

Multiply the numbers in RHS,

⇒ SI = Rs. 1170

Now find the amount,

⇒ A = SI + P

Subtitute the values,

⇒ A = Rs. 1170 + Rs. 3900

Add the sum,

⇒ A = Rs. 5070

∴ So, the amount is Rs, 5070.

i hope it will help you