ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Pre-Algebra Videos 36 videos
ACT Math Pre-Algebra Drill 2, Problem 5. Given the chart in the video, what is the mode?
ACT Math Pre-Algebra: Drill 3, Problem 5. Simplify the expression.
ACT Math 4.4 Pre-Algebra 509 Views
Share It!
Description:
ACT Math: Pre-Algebra Drill 4, Problem 4. Using the information given, find out how many girls attend the school.
Transcript
- 00:03
Here's your shmoop du jour:
- 00:04
The ratio of boys to girls at the local middleschool is 3 to 4.
- 00:08
If there are 245 students at the school, how
- 00:11
many girls are there?
- 00:13
And here are the potential answers...
Full Transcript
- 00:19
So obviously this is a GREAT school to attend if you're a boy who likes going out Saturday nights.
- 00:24
It's a simple ratio problem. The problem tells us that the boys to girls ratio is:
- 00:31
3x boys and 4x girls. Meaning... there are more girls than boys...
- 00:38
It also gives the TOTAL number of students, which is 245.
- 00:41
There's a simple ratio here. 4 out of 7 students are girls.
- 00:45
So the ratio is "4 is to 7 as x is to 245."
- 00:53
To get the answer, we cross multiply to get 7x equals 4 times 245...
- 00:58
...or 7x equals 980.
- 01:02
To solve for x... which is the number of boys in the school... we divide both sides by 7
- 01:07
to get x = 140.
- 01:09
The answer is E.
- 01:10
As in, "Edwina."
Related Videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.
SAT Math 10.3 Geometry and Measurement. What is the ratio of birds to dogs?
SAT Math 2.1 Statistics and Probability. Which two items have the highest protein to fat ratio?