A winery has a barrel to hold chardonnay. An inlet pipe can fill the barrel in 15 hours, while an outlet pipe can empty the barrel in 20 hours. How many hours would it take to fill the barrel if both the inlet and outlet pipes are open? Express your answer as a fraction reduced to lowest terms, if needed.

60 hours

Step-by-step explanation:

Let X be the total capacity.

Inlet speed: X/15

Outlet speed: X/20

Combined:

X/15 - X/20 = X/60

X/60 = X/time

Time = 60 hours

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads

answer: 80,000

step-by-step explanation:

the population doubles every day.

10,000*2=20,000 day 4

20,000*2=40,000 day 5

40,000*2=80,000 day 6