Ileft home going to the movies. i had $90 when i left the house. i spent 31/45 on tickets, and out of the remaining cash i spent 1/7 on food n drinks.so how much money do i have left?

First you can find  of 90. 

90 x  = 62

Next, you have $62 left and spent   of it. Meaning you have  of 62 left.

62 x   = about 53.14285

As your answer is not a whole number, you could round according to whatever guidelines your homework has given you (for example - rounding to the 2nd decimal place $53.14)

do the dirty all night long