i was going to answer but siomeome beat me lol but hdjwStep-by-step explanation:
ANSWER
The slant height is 40cm.
EXPLANATION
The lateral area of a cone is given by:

where r=10cm is the radius of the circle and l is the slant height.
It was also given that, the lateral area is 400π cm²
We substitute the values to get,

We now divide both sides by 10π.
This implies that,


Hence the slant height is 40cm.
D should be correct
Sorry if it’s wrong
1.5 cups = 0.09375 gallon
per week = 7 days
So, 0.09375(7) =0.65625 gallon /week
Or you could round it to 0.66