Answer: It takes 1.5 hours for them to do the work together.
Explanation:
Since we have given that
Number of hours his new four wheel drive truck takes = 2 hours
Number of hours his neighbour can plow out takes = 6 hours
We need to find the number of hours they work together.
According to question, it becomes,

Hence, it takes 1.5 hours for them to do the work together.