Level 3
Ronnie and Dave, together, can clean a room in 3 hours. If Ronnie is cleaning the room alone, he can only complete the task in 9 hours. How long will Dave take to clean a room all by himself? Express the answer in mixed number.
Level 3
8 workers take 10 hours to build 4 bookshelves. How many hours will 6 workers take to build 2 bookshelves? Express the answer in mixed number of hours.
Level 3
50 men working 8 hours a day can finish building a boat in 10 days. How long would it take 60 men to finish building the same boat if they work the same number of hours a day?
Level 3
Machine X takes 5 minutes to cut 85 pieces of lumbers.
Machine Y takes 15 minutes to cut 120 pieces of lumbers. Machine Z takes 10 minutes to cut 120 pieces of lumber.
Which is the faster combination, X and Y or Y and Z? (Eg A, B)
In 1 minute, how many more pieces of lumbers can be cut by the faster combination compared to the other combination?
Level 3
It takes Faucet A 30 minutes to fill a tank measuring 12 cm by 10 cm by 22 cm completely while it takes Faucet B only 25 minutes. How long will it take to completely fill the tank with water if both the faucets are turned on at the same time? Leave the answer in minutes and round off to 2 decimal places.
