Option A.
By working together they can finish 1 job in 180/5 minutes. So in 30 minutes they can complete 5/6 work. Now remaining 1/6 work will be completed by Larry in 90/6=15 minutes.
Sent from my XT1663 using GMAT Club Forum mobile app
By working together they can finish 1 job in 180/5 minutes. So in 30 minutes they can complete 5/6 work. Now remaining 1/6 work will be completed by Larry in 90/6=15 minutes.
Sent from my XT1663 using GMAT Club Forum mobile app







