Online Access Free SAT-Mathematics Exam Questions

In Marie's fish tank, the ratio of guppies to platies is 4:5. She adds nine guppies to her fish tank and the
ratio of guppies to platies becomes 5:4. How many guppies are in the fish tank now?

Correct Answer:

25
Explanation/Reference:
If the original ratio of guppies, g, to plates, p, is 4:5, then g =4/5pIf nine guppies are added, then the new
number of guppies, g + 9, is equal to5/4p: g+9 = 5/4p.Substitute the value of g in terms of p from the first
equation:4/5 p+9 = 5/4p,9 = 9/20p, =p = 20.There are 20 plates in the fish tank and there are now20(5/4)
=25guppies in the fish tank.

is equivalent to

• A.Option D
• B.Option C
• C.Option A
• D.Option B
• E.Option E

There are seven students on the trivia team. Mr. Randall must choose four students to participate in the
trivia challenge. How many different groups of four students can Mr. Randall form?

Correct Answer:

35
Explanation/Reference:
The order of the four students chosen does not matter. This is a "seven-choose-four" combination
problem-be sure to divide to avoid counting duplicates:

There are 35 different groups of four students that Mr. Randall could form.

What is the next number in the series below?
3 16 6 12 12 8

• A.24
• B.15
• C.4
• D.32
• E.20

If , then which of the following must be true?

• A.Option D
• B.Option C
• C.Option A
• D.Option B
• E.Option E