How to solve this equation

Set up an equation for each store by multiplying the cost of the basketball by the number of basketballs bought (b) and add the cost of the hoop:

Hoops House: total = 20b + 200

Baller Basement: total = 15b + 250

Now to solve for b, set the two equations equal to each other:

20b + 200 = 15b + 250

Subtract 15b from both sides:

5b + 200 = 250

Subtract 200 from both sides:

5b = 50

Divide both sides by 5:

B = 10

The answer is 10 basketballs

approximately 5 hours 32 minutes

let x be the amount of it takes both pumps to fill and 1 pump to empty

so the pumps fill/empty at the rate of per hour

first pump fills at a rate of per hour

second pump fills at a rate of per hour

third pump empties at a rate of per hour

together the reservoir fills at a rate of

+ - =

multiply each term by 720x

120x + 90x - 80x = 720

130x = 720 ( divide both sides by 130 )

x = = 5. hours

(0. × 60 ≈ 32 minutes )

time taken to fill reservoir is 5 hours 32 minutes