Answer:
Step-by-step explanation:
You have to distinguish the difference between a ratio of yellow bulb to red bulb and red bulb to total and yellow bulb to total. The totals are where you start.
2 bulbs out of 5 are yellow
3 bulbs out of 5 are red
Yellow
Set up the proportion for yellow. You could start with red.
Red
Note: Yellow to red is 2/3