Kanga covered each digit of a number with a shape. Equal digits have equal shapes, and different digits have different shapes. Which number could be hidden?
One animal sleeps in each basket. The koala and fox have baskets with the same pattern and shape. The kangaroo and ostrich have the same basket pattern. Which basket is the puppy’s?
Maria receives teddy bears on each birthday: 1 on her first, 2 on her second, and one more than the previous year on each following birthday. How many has she received altogether by her sixth birthday?
Dino enters at the left and exits at the right. He may pass through each room at most once. He adds the room numbers he visits. What is the greatest total?