Question

Titus works at a hotel. Part of his job is to keep the complimentary pitcher of water at least half full and always with ice. When he starts his shift, the water level shows 8 gallons, or 128 cups of water. As the shift progresses, he records the level of the water every 10 minutes. After 2 hours, he uses a regression calculator to compute an equation for the decrease in water. His equation is W –0.414t + 129.549, where t is the number of minutes and W is the level of water. According to the equation, after about how many minutes would the water level be less than or equal to 64 cups?

150 minutes
160 minutes
170 minutes
180 minutes
What are the values of a and b?

a = 0.4 and b = –0.15
a = –0.4 and b = 0.15
a = 8.6 and b = 14.25
a = –8.6 and b = –14.25

Answer 1

Answer: The equation for the decrease in water is given by:

W = -0.414t + 129.549

To find after about how many minutes the water level would be less than or equal to 64 cups, we can set W to 64 and solve for t:

64 = -0.414t + 129.549

-65.549 = -0.414t

t = 158.1

Rounding to the nearest 10 minutes, we get:

t = 160

Therefore, after about 160 minutes, the water level would be less than or equal to 64 cups.

Regarding the values of a and b, we can see that they are not relevant to this problem since they are not given in the equation for the decrease in water. So, none of the given options is correct.

Explanation: