A certain sum amounts to ₹5,200 in 2 years and ₹6,400 in 4 years at simple interest. What is the rate of interest per annum?
15 percent
Let the principal be \(P\) and the annual simple interest be \(I\).
From the given conditions: \(P + 2I = 5200\) and \(P + 4I = 6400\).
Subtracting the first equation from the second: \(2I = 1200 \Rightarrow I = 600\).
Substituting back: \(P = 5200 - 2 \times 600 = 4000\).
Rate of interest \(= \frac{I \times 100}{P} = \frac{600 \times 100}{4000} = 15\%\).
Hence, the rate of interest per annum is 15 percent.
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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?
