My First Attempt At Riddles

15 Points Per Correct Answer - No time limit  

1. I was walking through my hometown last week. Suddenly I ran into a friend of mine, that I hadn't seen for years. He's standing in front of his house. When I asked him about his kids, he told me he had three kids. He knew I always loved maths so he told me that the product of their ages equals his own age, 36. Seeing I was puzzled, he then told me to add up their ages, so I would get his housenumber. I looked at his housenumber, but still didn't know their age. Then I heard someone playing the piano inside the house. "Oh, that's my oldest kid playing", he told me. AND then I knew how old his oldest kid was. Do you know? 6 4 8 9

2. In a household, there are some boys and girls= at least 2 of each. Every girl has as many sisters as she has brothers. Every boy has twice as many sisters as brothers. How many boys and girls are in this household? Answer: (Numbers only. first boys then girls)

3. When you know it takes five cats five minutes to catch five mice, how long will it take for 100 cats to catch 100 mice? 100 minutes 500 minutes 50 minutes 5 minutes

4. I have a wooden cube of three by three by three centimeters. I paint all the surfaces white. After that, I'll take my saw and start sawing it in little cubes of one by one by one. I will have 27 cubes after some sawing. But how many of them will have NO white colour on any surface? Answer: (a number)

5. A bag of potatoes weighs fifty kilograms divided by half the weight of the bag of potatoes. What is the weight of the bag of potatoes in kilos? Answer: (a number (without kilo's behind it))