Question

The simple interest I on an investment of P dollars at an interest rate r for t years is given by I = prt. Find the time it would take to earn $900 in interest on an investment of $21,000 at a rate of 4.6%.

Answer 1

t=i/pr
t=900÷(21,000×0.046)
t=0.93167 y

Answer 2

I = prt
I/pr = prt/pr

t = I/pr
t = $900/$21000 x 0.046
t = $900/966
t = .9317 years