PaheliMaths riddles with answers
Twelve number riddles that need more thinking than calculating. Check each answer yourself: every one of them really works.
I am an odd number. Take away one letter and I become even. Which number am I?
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Seven. Take away the "s" and you get "even".
One grandmother, two mothers and two daughters sat down for tea. What is the smallest number of people at the table?
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Three: a grandmother, her daughter and her granddaughter.
How many times can you subtract 5 from 25?
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Only once. After that you are subtracting from 20.
A farmer has 17 goats. All but 9 run away. How many goats does he have left?
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Nine. "All but 9" means that 9 stayed.
Double me and add 6, and you get 20. Which number am I?
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7. Twice 7 is 14, and 14 plus 6 is 20.
Which is heavier: a kilogram of feathers or a kilogram of stones?
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Neither. Both weigh one kilogram.
I had 6 eggs. I broke 2, cooked 2 and ate 2. How many eggs are left?
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Four. The two I broke, cooked and ate were the same two eggs.
Water lilies in a pond double every day. On day 30 they cover the whole pond. On which day did they cover half of it?
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Day 29. They double the next day to cover all of it.
When my father was 31, I was 8. Now he is twice as old as I am. How old am I?
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23. He is always 23 years older, so he is twice my age when I am 23 and he is 46.
Using only addition, how can you make 1,000 with eight 8s?
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888 + 88 + 8 + 8 + 8 = 1,000.
Which three whole numbers give the same answer when you add them and when you multiply them?
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1, 2 and 3. Added or multiplied, they make 6.
A rope has to be cut into 6 equal pieces. How many cuts are needed?
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Five cuts.