Please help me with this :))

Do, h = (7, 9) (14, 18) the scale factor is

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236