Question

Mark (✓) against the correct answer
What number has to be added to each term of 3 : 5 to make the ratio 5 : 6?

(a) 6
(b) 7
(c) 12
(d) 11

Answer 1

(b) 7

Suppose that x is the number that is to be added.

Then, (3 + x) : (5 + x) = 5 : 6

$$\begin{gathered} \Rightarrow \frac{3+x}{5+x}=\frac{5}{6} \\ \Rightarrow 18+6x=25+5x \\ \Rightarrow x=7 \end{gathered}$$