Question

Robert borrowed $750 from his parents. He promised to repay the loan by giving his parents at least $67 from his paycheck each week Assuming Robert sticks to his promise, which of the following is NOT a possible scenario for the amount of debt Robert has remaining?

A.) after 5 weeks, Robert is $150 in debt

B.) after 6 weeks, Robert is $200 in debt

C.) after 7 weeks, Robert is $250 in debt

D.) after 8 weeks, Robert is $300 in debt

Answer 1

To answer this question we can propose the following equation:

`d=750 -x(67)`

Where:

x is the number of weeks elapsed.

d is the debt depending on the weeks.

Robert promised to pay at least $ 67 each week.

Therefore, after 5 weeks the debt of rober should be:

`d\leq750-5*67`

`d\leq415`

Then scenario A) is possible because
`150<415`.

After 6 weeks:

`d\leq750-6*67`

`d\leq348`

Then scenario B) is possible because
`200<348`.

After 7 weeks

`d\leq750-7*67`

`d\leq281`

Then scenario C) is possible because
`250 <281`.

After 8 weeks

`d\leq750-8*67`

`d\leq214`

So scenario D) is NOT possible because
`300>214`

Finally the correct answer is option D.