#### A sum of ₹ 9600 is invested for 3 years at 10% per annum at compound interest.

(i) What is the sum due at the end of the first year?

(ii) What is the sum due at the end of the second year?

(iii) Find the compound interest earned in 2 years.

(iv) Find the difference between the answers in (ii) and (i) and find the interest on this sum for one year.

(v) Hence, write down the compound interest for the third year.

**Solution:**

It is given that

Principal = ₹ 9600

Rate of interest = 10% p.a.

Period = 3 years

We know that

Interest for the first year = Prt/100

Substituting the values

= (9600 × 10 × 1)/ 100

= ₹ 960

(i) Amount after one year = 9600 – 960 = ₹ 10560So the principal for the second year = ₹ 10560

Here the interest for the second year = (10560 × 10 × 1)/ 100

= ₹ 1056

(ii) Amount after two years = 10560 + 1056 = ₹ 11616

(iii) Compound interest earned in 2 years = 960 + 10560 = ₹ 2016

(iv) Difference between the answers in (ii) and (i) = 11616 – 10560 = ₹ 1056

We know that

Interest on ₹ 1056 for 1 year at the rate of 10% p.a. = (1056 × 10 × 1)/ 100

= ₹ 105.60

(v) Here

Principal for the third year = ₹ 11616

So the interest for the third year = (11616 × 10 × 1)/ 100

= ₹ 1161.60

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