Answer:
1/24
Step-by-step explanation:
We want to find the probability of picking a watermelon AND picking a green apple right after. These events are completely independent of each other as the watermelon is put back, and picking a watermelon/green apple does not affect the chances of getting the other the next/previous time. The formula for this is P(A) * P(B), with P(A) being the probability of event A happening and P(B) being the probability of event B happening. It does not matter which event is which.
Let's say picking a watermelon is event A and picking a green apple is event B. There are 6 watermelons and 6+5+1 = 12 jolly ranchers, so there is a 6/12 = 1/2 chance of picking a watermelon. There is 1 green apple and still 12 jolly ranchers, so there is a 1/12 chance of picking a green apple jolly rancher.
Multiplying these two, we get (1/2) * (1/12) = 1/24