In Ryan's kitchen, there are 15 black tiles and 10 white tiles. What is the ratio (in the simplest form) of white tiles to black tiles?

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

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?

Square a has a side length of (2x-7) and square b has a side length of (-4x+18). how much bigger is the perimeter of square b than square a?and show all work! you so