Losing All Your Marbles: SAT Question of the Day

SAT Writing Question of the Day
SAT Writing – SAT Question of the Day
July 28, 2015
QOD2015_0707
Safety First: SAT Question of the Day
August 4, 2015
Show all

Losing All Your Marbles: SAT Question of the Day

QOD2015_0702
Explanation
This question asks us to relate parts to the whole using both total numbers and percentages. The long way to answer this question would be to calculate how many green marbles 25% represents, how many blue marbles 30% represents, then subtract this number from 80 and convert the number found to a percentage.

However, there is a much quicker route to the answer available. If we see that the bag is entirely composed of green, blue, and red marbles and 55% of the bag is made up of green and blue marbles, then consequently, the remaining marbles, all of which are red, must be equal to 45%.

This can be expressed as such:
25 + 30 + x = 100
x = 100 − 25 − 30
x = 100 − 55
x = 45

The correct answer is (B).

Comments are closed.