Answer:
Sorry, can't make a sentence, I can only give explanations. The choices would be nice though.
Explanation:
(Note: this is from my point of view and I used a solution that was thought to me, and since you haven't given the choices, I will be going in blind)
Step 1: Write it into a fraction (or ratio, depends on what you like)
Step 2: I would divide 45 by 5 to get the number that I will multiply the denominator with, after multiplying the denominator, you simply have to reconstruct to get the answer.
45 ÷ 5 = 9
9 x 2 = 18
Since there are 45 students that play golf, there are 18 students who play cricket.
Answer: 45 Students that play golf : 18 Students that play cricket
Another solution that I think was the one that is being explained here:
Step 1: Rewrite both into a fraction
=
Step 2: Cross multiply
Step 3: Simplify
÷
=
or 18 = x
x = 18