Answer:
6 hours
Step-by-step explanation:
Let both of them plan for t hours to plant 111 trees n t hours
Melissa can plants 10 trees in 1 hour
in t hours she can plant 10 t trees
Jane plants 17 tree in 2 hours
in one hour Jane can plant 17/2 trees
in t hours she can plant (17/2)t trees.
Total trees planted by both of them in t hours in terms of t will be
10t + (17/2)t
= (10t*2 + 17t)/2
= (20t + 17t)/2
= 37t/2
but it is given that they planted 111 trees together
so 37t/2 should be equal to 111
37t/2 = 111
=> 37t = 111*2 = 222
=> t = 222/37 = 6.
Thus, it takes 6 hours for both of them to plant 111 trees together.
