GMAT Question of the Day – Problem Solving – Ratio

In a bag of beads the ratio of red beads to blue beads to green beads is 2 to 75 to 20. A certain number of beads are added to the bag so that the ratio of blue beads to green beads is tripled while the ratio red beads to blue beads is halved. If after the additions there are 120 red beads, how many blue beads are there currently in the bag?

A. 3000

B. 3250

C. 3750

D. 7500

E. 9000

[spoiler]E.[/spoiler]

GMAT Question of the Day Solution

For GMAT ratio questions it helps to make a chart mapping out the relationships among the various entities. Some people give the ratio box a vertical layout but for whatever reason most GMAT tutoring students find the horizontal layout more intuitive. The three pieces of information that should be represented in your GMAT ratio box are:

1. The ratio – the most simplified relationship amongst the numbers.

2. The multiplier – what you multiply the ratio by in order to bring the ratio value to a real world value

3. The real values – the actual numbers of things

Once you have filled out the ratio box with the information from the question you’ll be much closer to solving this question of the day and many other GMAT ratio questions.