Question

The price for a gallon of gas is $4.99 how much is it going to cost for 20 gallons ?

Answer 1

if one gallon is 4.99, 20 gallons?

write a ratio to make it easier

gallon : price

1 4.99

20 x

cross multiply,

x = 20 × 4.99

x=99.8

Answer 2

You would have to put 4.99 times 20 which will cost 99.80 for 20 gallons.