Question

The value of y varies jointly with x and z. If y = 2 when z = 110 and x = 11, find the approximate value of y when x = 13 and z = 195.

Answer 1

y = 4

Explanation:

To find the approximate value of y when

x = 13 and z = 195 we must first find the relationship between them

The statement

y varies jointly with x and z is written as

y = kxz

where k is the constant of proportionality

From the question

y = 2

x = 11

z = 110

We have

2 = 11(110)k

2 = 1210k

Divide both sides by 1210

`k = (1)/(605)`

So the formula for the variation is

`y = (1)/(605) xz`

When

x = 13

z = 195

y is

`y = (1)/(605) (13)(195)`

`y = (507)/(121)`

y = 4.1900

We have the final answer as

y = 4

Hope this helps you