An oil tank has a capacity of 45 gallons.At the beginning of October it is 80% full.At the end of October it is 1/3 full.How many gallons of oil were used in October?

a. 21
b. 25
c. 41
d. 27
e. 30

my answer is (e)30, 45 x 1/3 =15 ,so 2/3 = 30

1 answer

45(.80 - 1/3) = 21

The tank was not full at the beginning of the month, but only 80% full, or 36 gallons.