A National Trend Predicts That Women Will Account for Half

Short Answer

A national trend predicts that women will account for half of all business travellers in the next 3 years.To attract these women business travellers,hotels are providing more amenities that women particularly like.A recent survey of Australian hotels found that 70% offer hairdryers in the bathrooms.Consider a random and independent sample of 20 hotels.
-Find the probability that more than 7 but less than 13 of the hotels in the sample offered hairdryers in the bathrooms.