At the movie theatre child admission is 5.40 and adult admission is 9.10 . On Friday 154 tickets were sold for a total sales of 1135.00 . How many child tickets were sold that day?

Answer 1

[100 + 54] 910 + 291.60 = 1,201.60 (too much)

[90 + 64] 819 + 345.60 = 1,164.60 (too much)

[80 + 74] 728 + 399.60 = 1,127.60 (too little)

so answer is between 65 and 73 child tickets

1,135.00 - 1,127.60 = 7.40

9.10 - 5.40 = 3.70

7.40 / 3.70 = 2

so adjusting [80 + 74] by that 2 ...

[82 + 72] 746.20 + 388.80 = 1,135.00

Answer: 72 child tickets (and 82 adult tickets)