Question

A carpenter can do a job in eight hours. His assistant can do the same job in ten hours. How long would it take them to do the job together?

Answer 1

Answer: 40/9 hours

Step-by-step explanation:

The carpenter can do a job in eight hours. Assuming he works at a steady pace, we can say he does 1/8 of the total job per hour.

The assistant can do a job in ten hours. He does 1/10 of the total job per hour.

Now, to find how much they do together per hour, we can add 1/8 to 1/10.

5/40 + 4/40 = 9/40

So, we know that together, the carpenter and his assistant can do 9/40 of the job in an hour.

We can then put x as the amount of time it took for them to do it together, so the equation would be: x = 1/(9/40), with 1 referring to the total amount of work. x would be equal to 40/9, so the answer is 40/9 hours of work, which can be converted to 4 and 4/9.