Question

Question

Answer 1

Answer:

3 hrs

Step-by-step explanation:

Thinking process:

Time taken by Sam = 4 hours

Time taken by Dave = 2 hours

Raking the lawn together will take them half the time each takes, so:

Sam = $0.5*4$

       = 2 hrs

Dave = $0.5 * 2$

         = 1 hr

Adding the hours gives = 2 + 1

                                        = 3 hrs

Answer 2

Answer:

1 hr 15 min

    or...

1.25 hrs

Step-by-step explanation:

Sam = 1/4 job = 1 hr

Dave = 1/2 job = 1 hr

1/4 +1/2 = 3/4

3/4 in one hour.

Thus they would take 1.25 hours to do the job together.