Kenny spends $21.50 on fruit
6 oranges = 3 dollars
divide both sides by 6 to get $0.50
3 grapefruits = $3.60
divide both sides by 3 to get $1.50
multiply the $0.50 by the amount of oranges Kenny buys
multiply the $1.50 by the amount of grapefruits Kenny buys
add the two amounts to get the final amount of money Kenny spent on fruit
