Problem of the Week

A riddle problem is a question or statement intentionally phrased so as to require ingenuity in ascertaining its answer or meaning, typically presented as a game. Below is a list of the past problem of the week riddles in descending chronological order.

How Do You Measure Nine Minutes With Two Hourglasses?

POW: 02-05-2024

How can you measure nine minutes with have two hourglasses, one four minute and one seven minute?

Answer: Turn over both hourglasses at once. When the four-minute hourglass runs out, turn it over. When the seven-minute hourglass runs out, turn it over. When the four-minute timer runs out this time (eight minutes have elapsed), the seven-minute hourglass has been running for one minute. Now turn over the seven minute timer back over. When the timer runs out, nine minutes have elapsed.

Speaking In Riddles

POW: 01-29-2024

A man bumps into his mathematician friend on the street whom he hasn't seen in 5 years. The man asks the mathematician how old his children are. The mathematician, who always replies in riddles said, "I now have three children. The sum of their ages is equal to the number of windows on the building in front of you and the product of their ages equals 36." The friend then says "I need one more piece of information." The mathematician then replies "My youngest child has blue eyes." What are the ages of the mathematician's three children?

Answer: They are 6, 6, and 1.

Doubling

POW: 01-22-2024

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Answer: Nine Years.

Rounds Of Golf

POW: 01-15-2024

Robert and David played several golf matches against each other in a week. They played for a pizza at each match, but no pizzas were purchased until the end of the week. If at any time Robert and David had the same number of wins, those pizzas were canceled. Robert won four matches (but no pizzas), and David won three pizzas. How many rounds of golf were played?

Answer: Eleven, David won 7 matches, 4 to cancel out Robert's 4 wins, and 3 more to win the pizzas.

When Asked How Old She Was Suzie Replied In Two Years

POW: 01-08-2024

When asked how old she was, Suzie replied, "In two years I will be twice as old as I was five years ago." How old is she?

Answer: She's 12!

Math Equation Riddle

POW: 01-01-2024

81 x 9 = 801. What must you do to make the this equation true?

Answer: Turn it upside down. 108 = 6 x 18.

Make The Equation True

POW: 12-18-2023

How can you make the following equation true by drawing only one straight line: 5+5+5=550? Can you figure it out?

Answer: Draw a line on the first plus sign that turns it into a 4! The equation then becomes true: 545+5=550. You could also change the equal symbol to a crossed out equal symbol which means "not equal to".

Strange Subtraction

POW: 12-04-2023

How can you take 2 from 5 and leave 4?

Answer: F I V E Remove the 2 letters F and E from five and you have IV which is the Roman numeral for four.

What Is The Next Number In The Series 7,645

POW: 11-27-2023

What is the next number in the series? 7,645 5,764 4,576...

Answer: 6,457. The last digit is moved to the front to make the next number.

Handshaking

POW: 11-20-2023

If seven people meet each other and each shakes hands only once with each of the others, how many handshakes will there have been?

Answer: Twenty one. Most people would think there were 42 handshakes. The first person shakes the hand of 6 others, the second person shakes the hand of 5 remaining people, the third person shakes the hand of 4 remaining people, the fourth person shakes the hand of 3 remaining people, the 5th person shakes the hand of 2 remaining people and the sixth person shakes the hand of 1 remaining person. 6+5+4+3+2+1=21