Question

The simple interest on a certain sum of money invested at a certain rate of 2 years amounts to rs. 1200. The compound interest on hte same sum of money invested at the same rate of interest for 2 years amounts to rs. 1290. What was the principal?

Answer 1

Answer:

4000

Step-by-step explanation:

Given  

The simple interest on a certain sum of money invested at a certain rate of 2 years amounts to rs. 1200. The compound interest on the same sum of money invested at the same rate of interest for 2 years amounts to rs. 1290. What was the principal?

We know that difference between simple interest and compound interest = 1290 – 1200 = 90

Now simple interest for 2 years = 1200

So simple interest for first year is Rs 600

90/600 x 100 = 15%

So for 15% interest is Rs 600

So for 100 it will be 600 x 100 / 15 = Rs 4000

So principal amount is Rs 4000

Answer 2

Answer:

4000

Step-by-step explanation:

First year Intrest=1200/2=600

Difference=90

Rate====90/6=15%

15%======600

100%======4000₹