Which function is graphed?
(Help please)

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

Christine went shopping and bought each of her six six nephews a? gift, either a video costing? $14.95 or a cd costing? $16.88. she spent ? $ 97.42 97.42 on the gifts. how many videos and how many cds did she? buy?

Can someone me and do the problem plz so i can understand it more better