Question

Find the missing number that makes the ratio equivalent to 1:7.
6 :

Answer 1

Let the missing number be a, then 1:7 and 6:a are equivalent.

As they are equivalent,
1:7 = 6:a
$\frac{1}{7}=\frac{6}{a}$

Let's cross multiply
$a\times 1=7\times 6$
$\therefore a=42$

Hence, the missing number is $42.$