Rohan deposited ₹500 for 2 years, ₹650 for 4 years and ₹1,300 for 6 years, at the same rate of interest. He received the total simple interest of ₹1,140. What is the rate of interest per annum?
10%
Using the simple interest formula: SI = (P × R × T) ÷ 100
Total interest from all deposits:
(500 × R × 2) ÷ 100 + (650 × R × 4) ÷ 100 + (1300 × R × 6) ÷ 100 = 1,140
(1000R + 2600R + 7800R) ÷ 100 = 1,140
11,400R ÷ 100 = 1,140
R = (1,140 × 100) ÷ 11,400 = 10%
Thus, the correct answer is 10%.
Important Questions from Simple Interest
Anil lent a sum of Rs. 5,000 on simple interest for 10 years in such a way that the rate of interest is 6% per annum for the first 2 years, 8% per anmum for the next 2 years and 10% per annum beyond 4 years. How much interest (in Rs.) will he earn at the end of 10 years?
What will be the simple interest on a sum of Rs. 12000 at the rate of 15 percent per annum for three years ?
If in 13 years fixed sum doubles at simple interest, what will be the interest rate per year? (correct to two decimal places)
On simple interest a sum of Rs. 640 becomes Rs. 832 in 2 years. What will Rs. 860 become in 4 years at the same rate of simple interest?
A certain sum amounts to Rs. 81840 in 3 years and to Rs. 92400 in 5 years at x% p.a. under simple interest. If the rate of interest is becomes (x + 2)%, then in how many years will the same sum double itself?
