Question

A natural number, when increased by 12, equals 160 times its reciprocal. Find the number.

Options

• 3

• 8

• 4

• 7

Answer 1

8

Explanation:

Let the number be x

Then according question,

x + 12 = ${\displaystyle \frac{160}{\text{x}}}$

x² + 12x – 160 = 0

x² + 20x – 8x – 160 = 0

(x + 20) (x – 8) = 0

x = –20, 8

Since the number is natural, so we consider only positive value.