Choice (A) has zero slope becsuse her cost doesn't depend on the number of visits.
Let y be the temperature
Let m be the rate of temperature drop in degrees per hour
Let x be the number of hours elapsed since 8PM
The initial temperature (at x = 0) is 0
y = mx
Four hours from 8 PM, the temperature was -16.8 degrees
-16.8 = m(4)
m = -4.2 degrees per hour
At 9PM, one hour will have elapsed.
y = -4.2(1)
y = -4.2 degrees
18+12*4=18+48=66 ft
1st floor is 18ft
next 4 are 12ft
You have to decide all sides to figure out all the kissing pieces
They can drink 51. Is my answer