Question

Carlos has 4 fifths of a tank of fuel in his car. He uses 1 tenth of a tank per day. How many days will his fuel last?

Answer 1

8 days because 4/5 = 8/10 and he is using 1/10 a day.

Answer 2

4 fifths and 1 tenth can be represented as fractions.

4/5 and 1/10

To find out how much he uses per day, we must subtract 4/5 from 1/10. BUT, before we do that, we must create a common denominator.

1/10 cannot be reduced, but 4/5 can be multiplied by 2 to make 8/10.

Now we can perform our equation:

$8/10 - 1/10 = 7/10$

He would have 7/10 of gas left after one day. If this went on, his fuel would last for 8 total days.