Question

Find the third proportional to 16 and 40

• A. 240
• B. 100
• C. 400
• D. 250

Answer 1

The correct option is B

100

Let $x$ be the third proportional

Then 16, 40 and $x$ are in continued proportion

$\therefore$ 16: 40 ::40 : $x$ $\Rightarrow 16x=40\times 40$

$\Rightarrow x=\frac{40\times 40}{16}$

$x$ = $\frac{1600}{16}$

$x$ = $100$