Question

Use the formulae to find simple interest and amount.

Example	Principal Rs	Rate of interest p.c.p.a	Number of years
(1)	9,000	10	3
(2)	15,000	11	2
(3)	50,000	9	4
(4)	1,25,000	12	2
(5)	1,50,000	10	3

Answer 1

(1) Principal = Rs 9,000
Rate of interest = 10% p.a.
Number of years = 3 years
Simple Interest $=\frac{\mathrm{Principal}\times \mathrm{Rate}\times \mathrm{Time}}{100}=\frac{9,000\times 10\times 3}{100}=\mathrm{Rs}2700$
Amount = Principal + Interest = 9,000 + 2,700 = Rs 11,700
∴ The simple interest is Rs 2,700.
And amount is Rs 11,700.

(2) Principal = Rs 15,000
Rate of interest = 11% p.a.
Number of years = 2 years
Simple Interest$=\frac{\mathrm{Principal}\times \mathrm{Rate}\times \mathrm{Time}}{100}=\frac{15,000\times 11\times 2}{100}=\mathrm{Rs}3300$
Amount = Principal + Interest = 15,000+ 3,300 = Rs 18,300
∴ The simple interest is Rs 3,300.
And amount is Rs 18,300.

(3) Principal = Rs 50,000
Rate of interest = 9% p.a.
Number of years = 4 years
Simple Interest $=\frac{\mathrm{Principal}\times \mathrm{Rate}\times \mathrm{Time}}{100}=\frac{50,000\times 9\times 4}{100}=\mathrm{Rs}18000$
Amount = Principal + Interest = 50,000 + 18,000 = Rs 68,000
∴ The simple interest is Rs 18,000.
And amount is Rs 68,000.

(4) Principal = Rs 1, 25,000
Rate of interest= 12% p.a.
Number of years = 2 years
Simple Interest $=\frac{\mathrm{Principal}\times \mathrm{Rate}\times \mathrm{Time}}{100}=\frac{125,000\times 12\times 2}{100}=\mathrm{Rs}30000$
Amount = Principal + Interest = 1,25,000 + 30,000 = Rs 1,55,000
∴The simple interest is Rs 30,000.
And amount is Rs 1,55,000.

(5) Principal = Rs 1,50,000
Rate of interest = 10% p.a.
Number of years = 3 years
Simple Interest $=\frac{\mathrm{Principal}\times \mathrm{Rate}\times \mathrm{Time}}{100}=\frac{150,000\times 10\times 3}{100}=\mathrm{Rs}45000$
Amount = Principal + Interest = 1,50,000 + 45,000 = Rs 1,95,000
∴ The simple interest is Rs 45,000
And amount is Rs 1,95,000.