A grocery store sells tangerines in 1/5 kg bags. A customer bought 3 kg of tangerine for a school party. How many bags did he buy?

Having a hard time understanding this question (see attachment).

Atown has a population of 17000 and grows at 2.5% every year. to the nearest year, how long will it be until the population will reach 19600?

Arestaurant offers delivery for their pizzas. the total cost the customer pays is the price of the pizzas, plus a delivery fee. one customer pays $23 to have 2 pizzas delivered. another customer pays $59 for 6 pizzas. how many pizzas are delivered to a customer who pays $86?