division world problems

Question

If a car travels 12.5 km on 1L of gasoline, how many litres of gasoline does it use when it travels 100 km?

Answer 1

Dear Christopher,

     There is a proportional way of thinking about it, too. 

 

12.5 km = 1 L

 

 

100 km = X  unknown amount of gas in liters

 

 

Set up a proportion:     km/ l   = Km/ l        12.5 km /1 L   = 100 Km/X

 

 

Cross multiply:    12.5X = 100      Then divide by the number next to "X."

 

If you like my method, please give me a thumbs up.

 

                                                                           Susan C.

 

Answer 2

Let r=the distance traveled on 1L of gasoline = 12.5 km/L

Let x=the amount of gasoline used when the car travels 100 km

d= distance travel =100 km

 

Hence,

 

r*x=d The unknown is x.

 

x=d/r=100/12.5=8L

 

Therefore, the car uses 8L of gasoline to travel 100 km.