Answer:
3 hrs
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 =
= 2 hrs
Dave =
= 1 hr
Adding the hours gives = 2 + 1
= 3 hrs
9.4m questions
12.2m answers