Question

A survey of 520 adults aged 18-24 year olds was conducted in which they were asked what they did last Friday night. It found:

172 watched TV
156 ate pizza
38 watched TV and ate pizza, but did not hang out with friends
36 watched TV and hung out with friends, but did not eat pizza
40 hung out with friends and ate pizza, but did not watch TV
38 watched TV, hung out with friends, and ate pizza
63 did not do any of these three activities
How may 18-24 year olds (of these three activities) only hung out with friends last Friday night?

Your Answer:

Answer 1

To find out how many 18-24 year olds only hung out with friends last Friday night, we need to subtract the number of people who engaged in other combinations of activities from the total number of people surveyed:

Total surveyed = 520

Watched TV only = 172 - 38 - 36 - 38 = 60

Ate pizza only = 156 - 38 - 36 - 40 = 42

Watched TV and ate pizza = 38

Did not do any of these three activities = 63

Therefore, the number of 18-24 year olds who only hung out with friends last Friday night can be calculated as follows:

Only hung out with friends = Total surveyed - (Watched TV only + Ate pizza only + Watched TV and ate pizza + Did not do any of these three activities)

Only hung out with friends = 520 - (60 + 42 + 38 + 63)

Only hung out with friends = 217

Therefore, 217 out of the 520 18-24 year olds surveyed only hung out with friends last Friday night.