Simple Interest = $\frac{\mathrm{Principal\; x\; Time\; x\; Rate}}{100}$

Principal = GH₵ 350.00
Time = 4 years
Rate = 5

Simple Interest = $\frac{\mathrm{GH₵\; 350\; x\; 4\; x\; 5}}{100}$

Simple Interest = $\frac{\mathrm{GH₵\; 350\; x\; 20}}{100}$

Simple Interest = $\frac{\mathrm{GH₵\; 350}}{5}$

Note: 20 divides itself once and 100, 5 times.

Simple Interest = GH₵ 70.00

Note: 5 divides itself once and 350, 70 times.

Principal is the amount invested or loan taken

Time is the duration of the investment or the time for the loan to be paid. Its mostly in years (annum). If you are given months or weeks, convert to years

Rate is the percentage rate (%) that will be used to calculate the interest earned on the investment or the interest to pay on the loan

The principal = 600

The rate = 5

Since the time was given in months, convert to years since the rate was per annum

There are 12 months in a year so divide the 8months by 12 months to get the yearly equavalent of 8 months

4 goes into 8, 2 times and 12, 3 times

Substitute the values into the simple interest formula

3 goes into 60, 20 times and itself once

The zeros cancels each other

Simple interest = 2 x 2 x 5 = 4 x 5 = 20

Interest = Principal x Time x Rate / 100

Interest = 240, Time = 4 and Rate = 20

⇒ 240 = Principal x 4 x 20 / 100

Multiply both sides by 100 and simplify 4 x 20 (80)

⇒ 240 x 100 = 80 x Principal

Divide both sides by 80 so that Principal can be alone at one side of the equation

240 x 100 / 80 = Principal

80 goes into 240, 3 times

⇒ 3 x 100 = Principal

⇒ Principal = 300

Interest paid = GH₵ 30

Time = 4 years

Rate = 3%

Amount borrowed is the principal.

$\frac{\mathrm{Principal\; x\; 4\; x\; 3}}{100}$ = 30

Get rid of the fraction by multiplying both sides by the denominator , 100

$\frac{\mathrm{Principal\; x\; 4\; x\; 3}}{100}$ x 100 = 30 x 100

Principal x 4 x 3 = 30 x 100

Divide both sides by 4 x 3

Principal = $\frac{\mathrm{30\; x\; 100}}{\mathrm{4\; x\; 3}}$ = 10 x 25 = 250

Notes:

1. 3 divides itself 1 time and 30, 10 times
2. 4 divides itself 1 time and 100, 25 times
3. 10 x 25 = 250

∴ amount borrowed = GH₵ 250.00