Which set of ratios form a proportion? 6/8 and 15/20
12/15 and 18/24
9/10 and 19/20
20/30 and 30/40

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Agraphic designer created a logo on eight and a half by 11 inch paper. in order to be placed on a business card, the logo needs to be one and 7/10 inches by 2 and 1/5 in. what is the scale factor of the dilation

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?