How do you spot a fraction?

Last updated: 13 Oct 2008

In the GMAT fractions are often disguised as percentages or decimals.

We have already seen that 0.125 is equal to 1/8. How did we know that?

The easiest way to have these fractions at your fingertips is to memorize them.

Fractions, percentages and decimals

This table shows the most commonly used fractions (in the GMAT) and their decimal and percent equivalents.

FractionDecimalPercentage
1/2 0.5 50%
1/3 0.333... 33%
2/3 0.666... 66%

You will notice that one third is written 0.333... , that is to say the 3 repeats an infinite number of times. This is one of the other advantages of fractions, some numbers cannot be written down in decimal form.

FractionDecimalPercentage
1/4 0.25 25%
3/4 0.75 75%

Why didn't we include 2/4 ?

Because we have already included it in the table. 2/4 = 1/2

FractionDecimalPercentage
1/5 0.2 20%
2/5 0.4 40%

Followed by 60% and 80%.

FractionDecimalPercentage
1/6 0.1666... 16 2/3%
5/6 0.8333... 83 1/3%

You should be able to see why 2/6, 3/6 and 4/6 have not been included.

FractionDecimalPercentage
1/8 0.125 12.5%
3/8 0.375 37.5%
5/8 0.625 62.5%
7/8 0.875 87.5%
1/9 0.111... approximately 11%
2/9 0.222... approximately 22%

A clear pattern emerges from 1/9, 2/9...

FractionDecimalPercentage
1/10 0.1 10%
1/20 0.05 5%
1/100 0.01 1%

Do you think you can remember all that?

Take your time to review the fractions above and then see if you can do the exercise on the next page.

Next page: Exercise with fractions

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