Choice 1: Angela and Kellie went to lunch. Their bill before tax was $20.00. Tax is 8%. How much tax should they expect to pay?

Please help ASAP and anything would help thank you:)PS: these are percentages

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?