you know that the gas tank of your car holds 20 gallons of gas and the guage reads ¼ full. How many gallons will be needed to fill the tank. If the price of gas is $3.10 per gallon and you have $40, do you have enough cash to fill the tank? How much extra money do you have or how much are you short?

Answer 1

¼ tank =¼ * 20 = 5 gallons
so you still need 15 gallons
you know that 3*15 = 45, already more than you have available, so ...
you will be short 15*3.10 - 40