Bill Gates borrows $7000 from Zuckerberg at the rate of r% per annum. After 3 years he again borrows $3000 and paid a total of $5325 as simple interest after 8 years from the first time he borrowed the money. Find the value of ‘r’?
1). 5.5%
2). 9.5%
3). 7.5%
4). 12.5%
Total interest = interest on 7000 for 3 years + interest on 10000 for 5 years
According to the question,
⇒ (7000 × r × 3)/100 + (10000 × r × 5)/100 = 5325
⇒ (210 × r) + (500 × r) = 5325
⇒ 710 × r = 5325
Required rate of interest ‘r’ = 7.5%