Question

Given that A is directly proportional to B and that A = 5/3 when B = 5/6, find A when B=1/3 and B when A =15/2.

Answer 1

Explanation:

A is directly proportional to B is written as

A = kB

where k is the constant of proportionality

First we must find the relationship between the two variables

when

A = 5/3

B = 5/6

Substitute the values into the formula to find k

`(5)/(3) = k (5)/(6)`

Multiply through by the LCM which is 6

That's

`5 * 2 = 5k`

5k = 10

Divide both sides by 5

k = 2

So the formula for the variation is

A = 2B

when B = 1/3

`A = 2 * (1)/(3)`

`A = (2)/(3)`

When A = 15/2

`(15)/(2) = 2B`

Multiply through by 2

`4B = 15`

Divide both sides by 4

`B = (15)/(4)`

Hope this helps you