If y varies directly as x, and y = 7 when x = 3, find y when x = 7

Direct variation, by definition, has the form shown below:

y=kx  

Where k is the constant of proportionality.

Given the information in the problem, you can find k:

7=3k

k=7/3

Now you can find y when x=7 as following:

y=(7/3)x

Substitute values.

y=(7*7)/3

y=49/3

4 packs of water and 7 packs of candy bars

step-by-step explanation:

35x4=140

140/20=7