Three consecutive odd integers have a property: the product of the first and third integers is 33 less than eight times the middle integer. What is the middle integer?
5
Working backwards from the square of 100, the square root can be 10 or -10. If (3x - 5)^2 = 100, then 3x - 5 = 10 (or -10). Testing 10: 3x - 5 = 10 gives 3x = 15, so x = 5. Testing -10: 3x - 5 = -10 gives 3x = -5, which is not a whole number. Since we want a positive integer, the number is 5.
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: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
More math riddles
I am a geometric shape with no beginning and no end. My rotational symmetry is infinite, yet my area can be found using the square of my radius multiplied by a famous irrational constant. What am I?
I am a single-digit positive integer. If you square me, my last digit is equal to me. If you cube me, my last digit is still equal to me. I am not 0, 1, or 5. What number am I?
One party hat costs 5 dollars. How many dollars do 4 party hats cost?
I started a journey with a certain amount of cash. I spent half of it on lunch, then gave $5 to a friend. After that, I spent half of my remaining money on a book, and was left with $8. How much money did I start with?
Lily has 9 autumn leaves and finds 5 more. How many autumn leaves does Lily have now?
Using three identical single-digit numbers in an addition expression, how can you form a sum equal to 60 without using the number 20?