Find a three-digit number where the first digit equals the sum of the second and third digits, and the second digit is twice the third digit. The third digit is 2.
642
Third digit = 2. Second digit is twice the third, so 2 * 2 = 4. First digit is the sum of the second and third, so 4 + 2 = 6. The number is 642.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Easy. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
More math riddles
If yesterday was the day before Wednesday, what day of the week is tomorrow?
Lily makes 5 rows of 2 mittens and adds 4 more at the end. How many mittens are there in all?
Using only addition, how can you add eight 8s to get the number 1,000?
I am a polygon whose interior angles sum up to the exact same value as my exterior angles. How many sides do I have?
Three identical boxes contain fruit. One has only apples, one has only oranges, and one has both. Every single box is labeled incorrectly. If you are allowed to pull just one piece of fruit from a single box, which box must you pick from to fix all the labels?
You have an empty 3-liter jug, an empty 5-liter jug, and an unlimited water supply. What is the minimum number of steps needed to end up with exactly 4 liters in the 5-liter jug? (A step is filling, emptying, or pouring between jugs).