On his way to work adam noticed that his gas was 7/8

Question

On his way to work adam noticed that his gas was 7/8 full. During the day Adam used 1/4 of the remaining gas. At the end of the day what fraction of the tank of gas did Adam have

Answer 1

Great question that can be seen on standardize test. 

 

We need to be able to handle fractions, of course! Whenever adding and/or subtracting fractions you will need to find the Lowest Common Denominator (LCD). Test makers are notorious for putting "good" wrong answers.

 

Case in point, 7/8 - 1/4 = 6/4 would be an answer choice on a standardize test.

 

The correct way to handle this problem is:

 

7/8 - (2/2)1/4

 

7/8 - 2/8 = 5/8, which is roughly 62.5% full.

 

This makes sense as 87.5% - 25% = 62.5%.