Please help and can you please give an explanation.

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

Mrs. gehrke said cheddar weighs 16.8 pounds. he actually weighs 15.2 pounds. what is the percent error?

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.