Question

5. In an incoming class of 7th grade students, 75% of the students were 12 years old. If 96 of

the 7th grade students were 12 years old, which of the following is the total number of 7th
grade students? Show how you arrived at your answer.
(1) 72
(3) 136
(2) 128
(4) 144

Answer 1

Answer: 128 students

Explanation:

We will set up a proportion to help us solve.

`\displaystyle \frac{75\%}{96\;\text{students}} =\frac{100\%}{x\;\text{students}}`

Now, we will cross-multiply.

75 * x = 96 * 100

75x = 9,600

Lastly, we will divide both sides of the equation by 0.75.

x = 128