Question

find the interest when principal = rupees 640, time = 2 years, rate = 10% p.a

Answer 1

principal = 640rs,
time = 2 years,
rate = 10% p.a

interest = p×r×t/100
= 640×2×10/100
=64×2
=128 rs

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Answer 2

Principal= ₹640
Rate of interest= 10% p.a
Time= 2 years
$simple \: interest = \frac{p \times r \times t}{100}$
$s.i = \frac{640 \times 10 \times 2 }{100}$
=128