What affect does "k" have on the parent function y=1/x

Twelve friends shared 8 small pizzas equally.how many pizzas did each person get?

If a baby uses 15 diapers in 2 days, how many diapers will the baby use in a year?

Gregory draws a scale drawing of his room. the scale that he uses is 1 cm : 4 ft. on his drawing, the room is 3 centimeters long. which equation can be used to find the actual length of gregory's room?