A set of useful percent to fraction coversions that will save a lot of time when attempting problem solving questions in the GMAT Quant section.
Percentages Equivalent Fraction
16.66% or 16.67% 1/6
66.66% or 66.67% 2/3
6.66% or 6.67% 2/30 or 1/15
Let us say you have a question that states that a family spends 66.66% of its income and saves the rest. If its savings is USD 3000, how much did the family spend?
66.66% can be written as 2/3rd. So, the family spends 2/3rds of its income.
The balance that the family saves = 1 – 2/3 = 1/3rd of the income.
Savings = USD 3000 = 1/3rd the income
Hence, income = 3*3000 = USD 9000.
Trying to crack the same question keeping it in percent terms could lead to unsavory calculations.
The reverse is equally useful – fraction to percent conversion
In quite a few questions, your ability to relate a fraction in its equivalent percent terms will help you comprehend what is stated a lot better.
For instance, if the question says A completes a task in 10 days and B completes the same task in 5 days.
The fraction approach to finding how much work does A and B do in a day will be as follows:
A completes 1/10th of the work in a day. B completes 1/5th of the work in a day and then add the two fractions.
Alternatively, if you could convert these two fractions to their equivalent percent your understanding of the question is way better.
A completes 1/10 of the task in a day. In percent terms, that is 10%.
B completes 1/5th of the task in a day. In percent term, that is 20%.
So, when they work together, they will complete 30% of the work. This is way faster than adding the two fractions.
Bottom line, be conversant with the process of converting from percents to fractions and vice versa. You will find that you are able to get to the correct answer more effectively.