Respuesta :

30:12 divide by 2 = 15:6 divide by 3 = 5:2. There are 5 white for every 2 red (that's as simplified as it gets) :)
Unit rate means how many per 1, so your answer has to compare white cars per 1 red car (even if it's not a whole number).

You can reduce 30/12 to 15/6 then 5/2, but to get the unit rate you have to finish the division...

5 ÷ 2 = 2.5

So the unit rate is

2.5 : 1

2.5 white cars to every 1 red car.