7) John bought I pineapple, 1 bag of cherries and 3 watermelons at a fruit stand. The
pineapple cost $2.80, the bag of cherries cost $3.90 and the watermelons were each $1.80.
If he paid with a twenty dollar bill, how much change should he get back?

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

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?

If set d is not the empty set but is a subset of set e, then which of the following is true? d ∩ e = d d ∩ e = e d ∩ e = ∅