The ratio of spinsters to cats is 2 to 7. If there are 25 more cats than spinsters, how many spinsters are there?

A. 10
B. 12
C. 15
D. 18
E. 27

OA is A

What is the best approach to solving this question?

Hi Roland2rule,
Let's take a look at your question.

Let S denotes the spinsters and C denotes the cats, then
$$\frac{S}{C}=\frac{2}{7}$$
$$7S=2C ... (i)$$

If there are 25 more cats then spinsters, we can write it as,
$$C=S+25$$
Substitute C in eq(i), we get,
$$7S=2\left(S+25\right)$$
$$7S=2S+50$$
$$7S-2S=50$$
$$5S=50$$
$$S=\frac{50}{5}=10$$
When there are 25 more cats then spinsters, then there are 10 spinsters.

Therefore, Option A is correct.

Hope it helps.
I am available if you'd like any follow up.