Question

How many hours do they have to work before they go to the movies

Cell phone Plan A costs $70 per month and comes with a free $500 phone. Cell phone Plan B costs $50 per month but does not come with a phone. If you buy the $500 phone and choose Plan B, how many months is it until your cost is the same as Plan A's?
I got two different answers last time. One said 25 and the other said 11. Are either of them correct?

Answer 1

25 months

Explanation:

Plan A : $70 per month

Plan B : $50 per month + $500 as a one time cost.

So for A $70 a month would take 8 months to be at least $500

And for B it in those 8 months it would cost you $900

But we have to keep going up until they are equal

25*70 = 1750

(25*50) = 1250+500=1750

So yes 25 months is correct