Question

The money spent, M , purchasing burritos at a particular fast food restaurant varies directly with the number of burritos purchased, B . When 4 burritos are purchased, $18 is spent. How much money is spent if 20 burritos are purchased?

Answer 1

two ways to do:

18/4 to get $4.50
then multiply
20 * 4.5 to get $90

or

since 4 * 5 = 20
multiply 5 * 18 to get $90 aswell