Solve
x4 − 8x2 + 16 = 0

3/4 of a 6-ounce glass will be drunk by her in one hour.

Step-by-step explanation:

Given time = 2/3 of hour

                  = 2/3 (60)       As hour = 60 mins

                  = 120/3

                   = 40 mins

Given quantity of water = 1/2 of 6-ounce

                                      = 3 ounce

So,

  In 40 mins, water intake is 3 ounce

  In 1 min, water intake is 3/40

  In 60 mins, water in take is (3/40)*60 = 4.5 ounce

Quantity of water intake in 60 mins:

       4.5 ounce or 3/4 of 6-ounce glass