Ken and Ben were both saving money to buy a TV. Ken was $255 short of the amount needed and Ben was $315 short of the amount needed to buy the TV. If they combined their money, they had eaxctly enough to buy one TV. how much did the TV cost?

Answer 1

If they have enough together to buy a tv, then Ken must be short exactly what Ben has, and vice-versa. So, a tv costs 255+315 = 570.

or, algebraically, since a TV costs as much as they have together,

k = (k+b)-255
b = (k+b)-315

(k,b) = (315,255)
tv = k+b = 570