Ratios and Proportions in Numerical Reasoning

Often ratios and proportions problems are incorporated into aptitude tests by occupational psychologists to measure quantitative aptitude of an individual. Most people understand concepts of ratios however when it comes to performing calculations in numerical reasoning tests many don’t know where to begin. Hence, standalone knowledge of ratios is not sufficient. To be well prepared you have to gain experience in solving ratio problems in context of psychometric testing. Read the below paragraphs to find out how to work out problems related to ratios and proportions in numerical reasoning tests.


How to calculate ratios

When it comes to performing effective calculations of ratios in numerical reasoning ability tests there are few things you have to keep in mind. Below we will demonstrate how to work with ratios quickly and effectively. Consider the table and question below.


What is the ratio of bottle E to bottle D of vine?

To quickly calculate the above ratio, divide in your calculator 1,500 by 1,200. If you are performing this calculation in ‘Stats’ mode of your calculator then you would get 1.25. Remember, you don’t have to convert 1.25 to fraction in your head which takes time but rather use your calculator to convert it by pressing SD. SD in ‘Stats’ mode converts decimal into fraction. However, if you would perform the above calculation 1,500 / 1,200 in ‘Math’ mode you would get ratio in its lowest form instantly; that is 5/4. Now, the question may arise how to set the calculator into ‘Maths’ or ‘Stats’ mode? The best advice we can give here is to follow guide that comes along with your calculator, however, for those of you who use Casio fx-85ES press mode and choose 1: COMP (Math) or 2: STAT mode.


How to work out proportions

Now consider second question which will demonstrate and put into practice the above techniques on similar example.

If it is recommended to mix squash and water in the ratio of 2:5, then what would be the approximate fraction of water and squash left if 490ml drink was made from bottle B of squash and bottle D of water?

If you don’t know how to formulate necessary equation then see tutorial on direct proportions in numeracy tests which breaks down necessary steps to solve similar questions. However, to answer the above question in numerical reasoning test quickly make as many mental calculations as you can providing that these can be worked out quicker in your head than on your calculator. You can mentally add 2 with 5 and divide 490 by 7 and perform necessary multiplications of 2 with 70 and 5 with 70 in your head. Then subtract values and you will get the ratio of water to squash that is left as 550 : 180. If you have your calculator set up in ‘Stats’ mode and you will input 55/18 then you will get 3.05 and you can conclude that this approximately equals to ratio of 3:1. However, if you calculator will be set up in ‘Math’ mode you get 55/18. Remember, to convert fraction into decimal press SD to get 3.05.

To be quick in these calculations you have to invest time and train your mental aptitude on daily bases. You can view basic or more advanced topics in ratios and proportions test guide. Good luck with your test preparation.