I am a two-digit number. If you add the square of my first digit to the square of my second digit, you get 25. If you multiply my two digits together, you get 12. My first digit is smaller than my second. What am I?
34
The digits x and y must satisfy x^2 + y^2 = 25 and x * y = 12. The digits 3 and 4 satisfy both (9 + 16 = 25 and 3 * 4 = 12). Since x < y, the number is 34.
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: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
More math riddles
I am a two-digit number. My tens digit is twice my units digit, and the sum of my digits is 9. What number am I?
Two cars start driving toward each other from towns that are 300 miles apart. Car A travels at 60 mph and Car B travels at 40 mph. How many hours will it take for them to meet?
Ava has 7 tulips. Mia has twice as many. How many tulips do they have together?
A gift costs 12 dollars and you buy 3. How much do you spend?
I am a three-digit square number. My first digit is the square root of my third digit, and my middle digit is the sum of my first and third digits divided by 2. What number am I?
What positive whole number has the same result when you add it to itself as when you multiply it by itself?