Question

Y varies inversely as x, and y = 50 when x = 10. What is the value ofy when x = 20?
100

Answer 1

25

Explanation:

Since y varies inversely with x, the relation between y and x will be:

`y \propto (1)/(x)`

Introducing the proportionality constant, we can write:

`y = (k)/(x)`

Using the first set of given values of x and y, we get:

`50=(k)/(10)\\\\k = 500`

This means, the relation between y and x is:

`y = (500)/(x)`

We have to find y if x = 20. Using this value in above equation, we get:

`y=(500)/(20) \\\\ y = 25`

Thus y would be 25 if x is 20.