A hybrid car averages 600 miles on a 12.9 gallon tank of gas. Manuel is planning a 1240-mile vacation in his hybrid car. Find how many gallons of gas he can expect to burn.

the average distance travelled by the car - 600 miles

amount of gas used up - 12.9 gallons

therefore when he travels 600 miles he uses up 12.9 gallons

for every mile the amount of gas used up - 12.9 gallons / 600 miles = 0.0215 gallons / mile

therefore 0.0215 gallons used up per mile

so when he's going for 1240 miles - gas used up is 0.0215 gallons / mile x 1240 miles = 26.66 gallons

amount of gas needed is 26.66 gallons