Question

In a candy mix there are 4 green bars for every 3 red bars. How many red bars are there if there are 200 green bars?

Answer 1

150 red bars

4/3=200/150

Answer 2

4 Green bars = 3 Red bars 

200 Green bars = 150 Red bars
____________________________________

200/4 = 50

50 x 3 = 150

or 

You simply take 3/4 of whatever the value of green bars.