Question

If z varies inversely as w, and z=10 when w=0.7, how do you find z when w=20?

Answer 1

When `w= 20, z = 0.35`

Explanation:

As per data provided :
`z=10 ,` when `w =0.7`

As `z` is inversely proportional to `w:`

`color(blue)(z prop 1/w`

Introducing constant `k:`

`z = k xx 1/w`

`z = k/w`

`k = z xx w`

`k = 10 xx 0.7`

`color(blue)( k = 7`

Now, we are required to find `z` , when `w = 20.`

`z = k/w`

Substituting values for `k` and `w:`

`z = 7/20`

`z = 0.35`