As Tiana can clear the field in 3 hours,
it means she can clear in 1/3 per hour
Also, Jacob can do 1/2 of the work per hour.
now the rate we will determine when they are working together
so
hours are for completing:
Tiana = 3
Jacob = 2
Together = t have to find
so
Work done per hour:
Tiana = 1/3
Jacob = 1/2
Together = 1/t
by adding their work together
it will be
1/3 + 1/2 = 1/t now solve it
5/6 = 1/t
t = 6/2 = 1.2
1.2 hours they can clear the field
hope it helps