Question

At what rate percent per annum will rs 1625 amount to rs 2080 in 3 1/2 years

Answer 1

Given, principal = Rs 1625

amount = Rs 2080

time = 3 whole 1/2 = 7/ 2 yr = 3.5 yr

Find the interest :
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S.I = ( p × r × t ) / 100

S.I = 1625 × r × 3.5 / 100 = 5687.5 r / 100

= Rs 56.875r

solve for 'r' :
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amount = principal + S.I

2080 = 1625 + 56.875r

56.875 r = 2080 - 1625 = 455

56.875 r = 455

56875 r / 1000 = 455

56875 r = 455000

r = 8 %

Answer: required rate of interest = 8 %

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