Question of the Day

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May
7
2015
3,776 responses
Question of the Day Statistics
Number Answered
Correct 1,566
Incorrect 2,210
41% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer. 

In a class of 80 seniors, there are 3 boys for every 5 girls. In the junior class, there are 3 boys for every 2 girls. If the two classes combined have an equal number of boys and girls, how many students are in the junior class?

Answer Choices

Hint

The statement about 3 boys for every 5 girls means that out of every 8 students in the senior class, 3 are boys and 5 are girls. In other words, 3 over 8 of the class is boys and 5 over 8 is girls. Since there are 80 seniors, 3 over 8 of 80, or 30, must be boys and 5 over 8 of 80, or 50, must be girls. Let x stand for the total number of juniors and express, in terms of x, the number of junior boys and the number of junior girls. Then you can write an equation in x to represent the fact that the total number of boys (juniors and seniors) is equal to the total number of girls. Solving for x will give the total number of juniors.

Question of the Day

Can you answer today's question?

Register Next Tests:
6/6

May
7
2015
3,776 responses
Question of the Day Statistics
Number Answered
Correct 1,566
Incorrect 2,210
41% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer. 

In a class of 80 seniors, there are 3 boys for every 5 girls. In the junior class, there are 3 boys for every 2 girls. If the two classes combined have an equal number of boys and girls, how many students are in the junior class?

Answer Choices

Answer

Among the eighty seniors, there are 3 boys for every 5 girls, so 3 over 8 of the seniors, or 30, are boys and 5 over 8, or 50, are girls. Among the juniors, 3 over 5 are boys and 2 over 5 are girls. If x stands for the total number of juniors, then (3 over 5) times x are boys and (2 over 5) times x are girls. The total number of senior and junior boys is 30 plus ((3 over 5) times x). The total number of senior and junior girls is 50 plus ((2 over 5) times x). The question states that these quantities are equal, so 30 plus ((3 over 5) times x) = 50 plus ((2 over 5) times x). Solving this gives 150 + 3 times x = 250 + 2 times x, or x = 100.