Item 19 Your pump empties the water from a swimming pool in 6 hours. When your friend's pump is used together with your pump, the pool is emptied in 1.5 hours. How long (in hours) does it take your friend's pump to empty the pool when working alone

0.75 hours

Step-by-step explanation:

Time taken by my pump = 6 hours

Time taken by friend's pump = x

Combined time = 1.5 hours

Rate :

my pump = 1/6

Combined rate = 1/1.5

Combinwd rate = 1/6 + 1/x

Hence :

1/6 + 1/x = 1/1.5

(x + 6) / 6x = 1.5

x + 6 = 9x

x - 9x = - 6

-8x = - 6

x = - 6 / - 8

x = 0.75 hours

the function makes a strait line horizontally with no x intercept but a y intercept at 9.