how solve a ratio involving a fraction

Question

the ratio of cups of chopped onion to the number of cups of chopped cilantro in salsa is 4:3; if the recipe calls for 2/3 cups chopped onion, how many cups of chopped cilantro are needed?  How do I solve this?

Answer 1

Hey Samantha -- to go from 4 onions to 3 cilantros, "quarter the onion measure, then triple" ... 2/3, cut in half twice ... 1/3, 1/6 ... then triple ... 3/6 or 1/2 ... Best regards, ma'am :)

Answer 2

Hi Samantha,

The trick is to make each thing line up.

Onion: Cilantro

   4   :   3

  2/3 :   x

Well, 2/3 is just 4/6, so we are dividing the initial ratio by 6.  Divide the cilantro by 6 also and you'll see that you have 3/6 or 1/2 of a cup of cilantro.

Debbie