One inlet pipe can fill an empty pool in 16 hours, and a drain can empty the pool in 20 hours. How long will it take the pipe to fill the pool if the drain is left open? Express your answer as a reduced fraction.

360 different combinations

answer: a

step-by-step explanation:

10.2 units

d

step-by-step explanation:

the two points from this line are   (0,4)   & (2,-2)

we can call

now, lets find the slope (m):

now finding b (the y intercept). this is the point at the y-axis where the line cuts the axis. looking at the graph, it is y = 4. so the point is 4. hence b = 4

the slope-intercept form is given by  

putting the points, we have:

d is the correct answer.