How much was bill?

Question

Mike has $80 and Donna has $65. They went to lunch and each paid half the bill. The ratio of Mike's money to Donnas money was 7:4. How much was the bill?

Answer 1

Mike has $80, Donna has $65

they each paid half their lunch bill

the ratio of their money was 7:4

if they each paid half the bill and their remaining money was in a ratio of 7:4, let b= the bill,

then (80-b/2)/(65-b/2) = 7/4

320-2b = 455 - 7b/2

-2b+7b/2 = 455-320 = 135

3b/2 = 135

b = 135(2/3) 45(2) = approximately $90 = the lunch bill

each paid half = 45

80-45 = 35

65-45 = 20

35/20 = 7/4