"A" can mow a lawn in 2 hours while "B" can do so in 2.5 hours separately. If A & B work together, how long will it take for them to mow the lawn?

Ans is 1.112 hours (aprox) Lets say the lawn is 1000 sq mts A takes 1000/120 mins i.e. in one min = 8.334 mts B takes 1000/150 mins i.e. in one min = 6.667 mts Total time = x 6.66x + 8.33x = 1000 x = 66.67 (aprox) Therefore 1.112 hours (aprox)

In 1 hour, A can mow 1/2 the lawn. In 1 hour, B can mow 2/5 of the lawn. Together in 1 hour, they can mow 1/2 + 2/5 = 9/10 of the lawn. So to complete the lawn mowing, it will take them 10/9 hours. Its rare we have a Winner before a post from Saswat

Actually, I have already reached the limit : 3 wins/week. So I was not actually waiting for Today's puzzle. Congrats mayjune.