Question

If y varies directly as x, and y is 12 when x is 1.2, what is the constant of variation for this relation?

1
10
10.8
14.4

Answer 1

Hello,

y=k*x ; if x=1.2,y=12
==>12=k*1.2==>k=12/1.2==>k=10

Answer B

Answer 2

constant of variation is 10.

Second option is correct.

Explanation:

We have been given that y varies directly as x. Thus, we have

y = kx.............(1)

k is the constant of variation

Now, it has been given that when y is 12 then x is 1.2.

Hence, substituting x = 1.2 and y = 12 in equation (1)

12 = 1.2 k

Divide both sides by 1.2

k = 12/1.2

k = 10

Therefore, constant of variation is 10.

Second option is correct.