Question

Your grandmother gives you $1000 to start a college book fund. She tells you she will add $200to the fund each month if you will add $5 each month. After how many months will the college bookfund have $5715?

Answer 1

At first you have $1000

And she will add $200 if you add $5 each month

Let the number of months = x

so, each month you will add = 200 + 5 = $205

The total you will have after x months = y

y = 1000 + 205 x

So, we need to find x when y = $5715

5715 = 1000 + 205 x

solve to find x

205 x + 1000 = 5715

Subtract 1000 from both sides

205 x + 1000 - 1000 = 5715 - 1000

205 x = 4715

Divide both sides by 205

205x/205 = 4715/205

So, x = 4715/205 = 23

so, after 23 months the college book fund will be $5715