A person lent certain sum of money at the annual rate of 7 percent on simple interest and the interest received in 11 years is Rs. 920 less than the sum lent. What is the sum lent ?

Rs. 4000

Rate of interest per annum = 7%

Total rate in 11 years = 11 × 7 = 77%

⇒ 77% = \(\frac{77}{100}\)

It means,

Principal = 100 unit

Total Interest = 77 unit

ATQ,

⇒ (100 - 77) unit = Rs.920

⇒ (23) unit = Rs.920

⇒ 1 unit = Rs.40

Hence, 100 unit = 40 × 100 = Rs.4000