MathhhhhhhHhhhhh

Question

50% of the hotels have a restaurant and 40% have a swimming pool so 90% of the hotels in town have a restaurant or a pool

Answer 1

50% have a restaurant, 40% have a swimming pool

the percent that has one or the other is between 50% and 90%

If hotels that have restaurants do not have swimming pools, the 90% is the percent that have one or the other.

if the 40% that have swimming pools also have restaurants, then 50% is the percent that have one or the other.

Odds are the correct percent is somewhere between 50 and 90%

the percent that have one or the other = 40+50 - the overlap. the overlap is at most 40%

best guess might be 70%, the average of 50 and 90.

or construct a 100% confidence interval: 70 +/- 20%

at 70%, that would mean half the hotels that had swimming pools also had restaurants