Question

Find the value of $n$ such that

• A. $18$
• B. $20$
• C. $16$
• D. $2$

Answer 1

The ratios are equivalent,
Let's go through them one by one.
a. $6:5::n:15$
The ratios are equivalent
$\Rightarrow \frac{6}{5}=\frac{n}{15}$
On cross - multiplication,
$6\times 15=5n$
$n=18$
b. $2:4::8:n$
The ratios are equivalent
$\Rightarrow \frac{2}{4}=\frac{8}{n}$
On cross - multiplication,
$2n=32$
$n=16$
c. $3:4::15:n$
The ratios are equivalent
$\Rightarrow \frac{3}{4}=\frac{15}{n}$
On cross - multiplication,
$3n=4\times 15$
$n=20$
d. $8:12::n:3$
The ratios are equivalent
$\Rightarrow \frac{8}{12}=\frac{n}{3}$
On cross - multiplication,
$8\times 3=12n$
$n=2$