Question

Find an equation of joint variation. Then solve for the missing value.
a varies jointly as b and c.
One set of values is a = 2.4, b = 0.6, and c = 0.8.
Find a when b = 0.4 and c = 0.4.
a = 0.8
a = 1.2
a = 0.032
a = 1.6
Click on the correct answer

Answer 1

Answer:

a = 0.8

Step-by-step explanation:

a varies jointly as b and c.

This means that a can be written as a constant k multiplied by b multiplied by c, that is:

$a = kbc$

One set of values is a = 2.4, b = 0.6, and c = 0.8.

We use this to find the value of k:

$2.4 = k(0.8)(0.6)$

$0.48k = 2.4$

$k = \frac{2.4}{0.48}$

$k = 5$

So

$a = 5bc$

Find a when b = 0.4 and c = 0.4.

$a = 5bc = 5(0.4)(0.4) = 5(0.16) = 0.80$

The answer is a = 0.8.