Answer:
The constant of variation is 3
Step-by-step explanation:
Given.
And y is directly related to x
∝ 
Here k is constant of variation
--------------(1)
Put the and value in equation 1.
So, the constant of variation is 3.
The 1,000s place because she was in the 100s and you moved 6 to the left which makes the number higher.
G = gallons d = days
10g = 3d
?g = 1d
1g = ?d
-------------
for gallons in a day, divide 10g = 3d by 3
d = 10/3 gallons
3 and 1/3 gallons in a day
---------------
for days per gallon, divide 10g = 3d by 10
g = 3/10 days
1 gallon lasts 3/10 of a day
