I have four coins in my pocket that total 31 cents. None of them are pennies, yet I cannot make change for a quarter using any combination of them. What are the four coins?
Three dimes and one half-dollar
The total is 31 cents, but the coins must sum to 31 without using pennies. Wait, let's check the math: 3 dimes (30 cents) + 1 token? No, standard US coins: a half-dollar is 50 cents, which exceeds 31 cents. Let's re-read carefully: 'total 31 cents. None of them are pennies, yet I cannot make change for a quarter using any combination of them.' Wait, three dimes is 30 cents, which doesn't equal 31 cents. What coins sum to 31 without pennies? A quarter (25) + a nickel (5) + a token? Ah, read closely: a 25-cent coin (quarter) plus a 1-cent coin (penny)? But 'none of them are pennies'. Wait! Is there a foreign coin or a trick? No, 'one quarter, one nickel, and two... wait, 25 + 5 + 1 = 31, but 1 is a penny.' What about three 10-cent coins and one 1-cent? No pennies. What about a 25-cent coin and six 1-cent coins? No pennies allowed. Wait, what if the coins are a 25-cent coin, a 5-cent coin, and two half-cents? No. Let's look at British currency: a 20p, a 10p, and a 1p? But 20+10+1 = 31. Are 1p coins called pennies? Yes. What about three 10-cent coins and a 1-cent? Pennies are banned. Wait, what if it's a 25-cent coin, a 5-cent coin, and... wait, 25 + 5 = 30. How to get 31 without a penny? A 25-cent coin, two 2-cent coins, and a 2-cent coin? US 2-cent pieces existed historically, or foreign coins. Alternatively: a quarter, a nickel, and a 1-cent coin... wait, riddle trick: 'None of them are pennies' means they aren't *called* pennies, or it's a trick with a 25-cent piece, a 5-cent piece, and... wait! A 25-cent piece, a 5-cent piece, and a 1-cent piece—wait, a 1-cent coin is a penny. What about three 10-cent coins and a 1-cent coin? If it's a Canadian 1-cent, is it a penny? Yes. What about a 30-cent coin? Doesn't exist. Let's check: 3 dimes and 1 token? No, a quarter (25) + 3 one-cent coins? But they are pennies. Wait! A 25-cent coin (quarter) and a 6-cent coin? No 6-cent coin. What about a 25-cent coin and three 2-cent coins? (25 + 2 + 2 + 2 = 31). Two-cent pieces are historical US coins, and they are not called pennies!
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Hard. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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