Question

Find the simple interest, when:
(i) Principal $=Rs.2000$, Rate of Interest $=5\%$ per annum and Time $=5$ years.
(ii) Principal $=Rs.500$, Rate of Interest $=12.5\%$ per annum and Time $=4$ years.
(iii) Principal $=Rs.4500$, Rate of Interest $=4\%$ per annum and Time $=6$ months.
(iv) Principal $=Rs.12000$, Rate of Interest $=18\%$ per annum and Time $=4$ months.
(v) Principal $=Rs.1000$, Rate of Interest $=10\%$ per annum and Time $=73$ days.

Answer 1

(i) Principal (P) $=Rs.2000$
Rate of interest (R) $=5\%$ p.a.
Time (T) $=5$ years
Simple interest $=\frac{P\times R\times T}{100}=\frac{2000\times 5\times 5}{100}=Rs.500$
(ii) Principal (P) $=Rs.500$
Rate of interest (R) $=12.5\%$ p.a.
Time (T) $=4$ years
Simple interest $=\frac{P\times R\times T}{100}=\frac{500\times 12.5\times 4}{100}=Rs.250$
(iii) Principal (P) $=Rs.4500$
Rate of interest (R) $=4\%$ p.a.
Time (T) $=6$ months
T $=\frac{6}{12}$ years $=\frac{1}{2}$ year ($1$ year $=12$ months)
Simple interest $=\frac{P\times R\times T}{100}=\frac{4500\times 4\times \frac{1}{2}}{100}=\frac{4500\times 4\times 1}{100\times 2}=Rs.90$
(iv) Principal (P) $=Rs.12000$
Rate of interest (R) $=18\%$ p.a.
​Time (T) $=4$ months $=\frac{4}{12}=\frac{1}{3}$year ($1$ year $=12$ months)
Simple interest $=\frac{P\times R\times T}{100}=\frac{12000\times 18\times 1}{100\times 3}=Rs.720$
(v) Principal (P) $=Rs.1000$
Rate of interest (R) $=10\%$ p.a.
Time (T) $=73$ days $=\frac{73}{365}$ year ($1$ year $=365$ days)
Simple interest $=\frac{P\times R\times T}{100}=\frac{1000\times 10\times \frac{73}{365}}{100}=\frac{1000\times 10\times 73}{100\times 365}=Rs.20$