Answer
Plan A will pay for the computer faster (11 months, compared to 12 months with plan B).
Step-by-step explanation
Naomi wants to raise $840
She has two payment plans
We've been asked to find out which plan is faster.
Plan A
She pays $180 down and pays $60 weekly to reach $840.
After paying $180 down, she will have 840 - 180 = $660 to pay
Paying $60 weekly, she will pay $660 in (660/60) = 11 weeks
Plan B
She pays $0 down and pays $70 weekly to reach $840.
Paying $70 weekly, she will pay $840 in (840/70) = 12 weeks
We can easily see that plan A will pay for the computer faster (11 months, compared to 12 months with plan B).
Hope this helps!!!