Question

Mary invested $200 for 3 years at 5% per annum. John invested $300

at the same rate. If they both received the same amount of money in
simple interest, for how many years did John invest his money?​

a. 1 1/2
b. 2
c. 3
d. 10

Answer 1

b. 2

Step-by-step explanation:

Simple interest is calculated using the formula

I = p x r x t

Where p= principal amount

r= interest rate

t= time in years

Mary invested $200, at 5% for three years. She earned a simple interest of;

I= $200 x 5/100 x 3

=$200 x 0.05 x 3

=$30

If John received the same amounts, It means

$30= $300 x 0.05 x t

$30 = $15t

t= $30/$15

t=2

Time is 2 years