what does it mean when 2 ratios form a proportion??

3 ratios of 20/15???please help and hi if you go to sms

Are the ratios 25/45 and 15/27

2.Which of the following ratios is equivalent to 15/20? A.200 to 150<<< B.3:5 C.5/4 D.45 to 60 6.Whi...