Level 3
Min and Candy take 1 hour to clean the kennel together. If Min takes 3 hours to clean the kennel on her own, how long will it take Candy to clean the kennel alone?
Level 2
The ratio of the number of blue stickers to red stickers is 3 : 1.
After Adam buys another 10 blue stickers and 10 red stickers,
the ratio of the number of blue stickers to red stickers is 5 : 2.
How many stickers does Adam have now?