Question

If y varies inversely as x and y = 40 when x = 5, then the constant is

a.1/8
b.200
c.8

Answer 1

b. 200

Explanation:

We have been given that y varies inversely as x.

Since we know that equation that represents the inversely proportional relation between y and x is:
`y=(k)/(x)`, where,

k= Constant of proportionality.

Upon substituting our given values in above equation we will get,

`40=(k)/(5)`

Let us multiply both sides of our equation by 5.

`40* 5=(k)/(5)* 5`

`200=k`

Therefore, constant of proportionality for our given quantities is 200 and option b is the correct choice.

Answer 2

The answer is b. 200

If y varies inversely as x, then: y = c/x

We know:
y = 40
x = 5

y = c/x
c = y * x
c = 40 * 5
c = 200