1. 4 animals (1 pig , 1 dog, 1 cat, 1 cow)

2. a. 1 in 9

3. 177, 174 and 171

4. 21 rectangles

5. Three melons

6. Dale

7. a. (left) Sally; b. (Middle) Sue; c. (Right) Sarah

8. a. 69 birds b. 184 birds

9. Arrangement C

10. The child with the black hair is the girl, and the child with the white hair is the boy.
Since at least one of them lied, the only possibility is that they both lied, otherwise they would be two boys or two girls.