On the first day of june there were about 16.85 hours of daylight in a city. five months later there were about 5.50 hours of daylight. what was the percent decrease?

I'd say there was a percent decrease of approximately 67%.

Step-by-step explanation:

67.36%

Step-by-step explanation:

You would take 16.85 - 5.50 to find the decreased amount.  Then to find the percentage you would take that answer (11.35) and divide it by the original (16.85) and get 0.6735905, then you simplify and get 67.36%.

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