Help! need step by step instructions. Will become a fan and give you a medal (:

Your car gets 25 mi/gal around town and gets 30 mi/gal on the highway.
a. If 50% of the miles you drive are around town and 50% of the miles you drive are on the highway, what is your overall average miles per gallon?
b. If 60% of the miles you drive are on the highway and 40% is around town, what is your average miles per gallon?

Question

Help! need step by step instructions. Will become a fan and give you a medal (:

Your car gets 25 mi/gal around town and gets 30 mi/gal on the highway. 
a. If 50% of the miles you drive are around town and 50% of the miles you drive are on the highway, what is your overall average miles per gallon?
b. If 60% of the miles you drive are on the highway and 40% is around town, what is your average miles per gallon?

anonymous · Answer

a. 30+25=55
55/2=27.5 
27.5 is your average mpg
b. 25x4=100, & 30x6=180.
180+100=280
280/10=28
28 is your average mpg