steps you take, the less likely you will be to make a careless mistake.
Here’s another example. This one is quite a bit harder.
34.Forty percent of the members of the sixth-grade class wore white socks. Twenty percent
wore black socks. If twenty-five percent of the remaining students wore gray socks,
what percent of the sixth-grade class wore socks that were not white, black, or gray?
(Disregard the % when gridding your answer.)Here’s How to Crack It
The problem doesn’t tell you how many students are in the class, so you can plug in any number you like.
This is a percentage problem, so the easiest number to plug in is 100. Forty percent of 100 is 40; that
means 40 students wore white socks. Twenty percent of 100 is 20. That means that 20 students wore black
socks.
Your next piece of information says that 25 percent of the remaining students wore gray socks. How many
students remain? Forty, because 60 students wore either white or black socks, and 100 – 60 = 40.
Therefore, 25 percent of these 40—10 students—wore gray socks.
How many students are left? 30. Therefore, the percentage of students not wearing white, black, or gray
socks is 30 out of 100, or 30 percent. Grid it in, and remember to forget about the percent sign.
ORDER OF DIFFICULTY
Like all other questions on the Math Test, Grid-In problems are arranged in a loose order of difficulty.