At what rate percent per annum will a sum of Rs. 4000 yield compound i

1.	At what rate percent per annum will a sum of Rs. 4000 yield compound interest of Rs. 410 in 2 years?
Answer» Given details are, Principal = Rs 4000 Time = 2years CI = Rs 410 Rate be = R% per annum By using the formula, CI = P [(1 + R/100)ⁿ – 1] 410 = 4000 [(1 + R/100)² – 1] 410 = 4000 (1 + R/100)² – 4000 410 + 4000 = 4000 (1 + R/100)² (1 + R/100)² = 4410/4000 (1 + R/100)² = 441/400 (1 + R/100)² = (21/20)² By cancelling the powers on both the sides, 1 + R/100 = 21/20 R/100 = 21/20 – 1 = (21-20)/20 = 1/20 R = 100/20 = 5 ∴ Required Rate is 5% per annum.

At what rate percent per annum will a sum of Rs. 4000 yield compound interest of Rs. 410 in 2 years?

Answer»

Given details are,

Principal = Rs 4000

Time = 2years

CI = Rs 410

Rate be = R% per annum

By using the formula,

CI = P [(1 + R/100)ⁿ – 1]

410 = 4000 [(1 + R/100)² – 1]

410 = 4000 (1 + R/100)² – 4000

410 + 4000 = 4000 (1 + R/100)²

(1 + R/100)² = 4410/4000

(1 + R/100)² = 441/400

(1 + R/100)² = (21/20)²

By cancelling the powers on both the sides,

1 + R/100 = 21/20

R/100 = 21/20 – 1

= (21-20)/20

= 1/20

R = 100/20

= 5

∴ Required Rate is 5% per annum.