How much did the gas cost?

Question

You start driving at 8:30am and drive until 11:50am at 90 km/hr.  Your car gets 25mpg.  Gas costs $2.34 US per liter.  How much did it cost for the gas that you drove in US$?

Answer 1

 

If you drive from 8:30 until 11:50, you have driven 3 hours and 20 minutes. Since 20 minutes is a third of an hour, you've driven 3 1/3 or 3.33 hours. 

 

Since you're going 90 km/hr, and 90 times 3.33 is 299.7, you've driven 299.7 km.

 

I'm assuming that by mpg you mean miles per gallon, and 25 mpg is equal to 40 km/gal. 

 

Since you drove 299.7 km, divide that by 40 to find out how many gallons of gas you used, which is equal to 7.49.

 

Now you have to convert gallons to liters. 1 gallon is equal to 3.79L; 7.49 gallons is equal to 28.4 liters. So, you used 28.4 L of gas.

 

If each liter costs $2.34, then multiply this by 28.4 to find that the gas cost $66.46 USD...which is really expensive and this problem would make more sense if the gas was $2.34 for a gallon, which is approximately what gas costs. This price per liter is over $8/gallon.