Question

The sum of two number is 20 ; their product is 40 . The sum of their reciprocals is

• A. $\frac{1}{10}$
• B. $4$
• C. $2$
• D. $\frac{1}{2}$

Answer 1

The correct option is D $\frac{1}{2}$

Let the numbers are x and y
$\therefore$ x+y=20 and xy=40
Sum of the reciprocal of the numbers x and y
$\frac{1}{x}+\frac{1}{y}=\frac{y+x}{xy}=\frac{20}{40}=\frac{1}{2}$