What’s the answer answer

Question

A person can plow all the driveways on his street with his new four-wheel-drive truck in 6 hours. Using a snow blade on a lawn tractor, his neighbor can plow the same number of driveways in 9 hours. How long would it take them to do the work together?

Answer 1

the equation to solve is 1=x/6+x/9

complete job=x hour/6 + x hour/9

15x=54

x=3.6

Answer 2

1/6 + 1/9 = 1/X

multiply by 18X

3X + 2X = 18

5X = 18

X = 18/5 = 3.6 hours if working together

first guy does 1/6 the work in an hour, 2nd does 1/9 in an hour

together they do 1/X part of the job in one hour

1/6 + 1/9 + 1/X

1/6 + 1/9 = 3/18 + 2/18 = 5/18 = 1/X

cross multiply: 5X = 18, X = 18/5 = 3.6 hours together.

Answer 3

The answer is 3.2 hours