Question

If y varies inversely as x, and y = 33 when x = 7, what is the constant and what is value of y when x=11?

Answer 1

We have that y = 21 when x = 11.

Explanation:

We solve this question by proportions, using a rule of three.

Since they vary inversely, we apply the inverse rule of three, that is, with lateral multiplication instead of diagonal.

33 - 7

y - 11

So

`11y = 33*7`

Dividing both sides by 11

`y = 3*7 = 21`

We have that y = 21 when x = 11.