439 Expert Riddles for Adults With Answers - page 5 of 5
Joey/Charlie share 50ml. Joey sips 1/2, Charlie 1/2 of rest, repeat...
This forms a geometric series: Joey = 1/2 + 1/8 + 1/32... Charlie = 1/4 + 1/16 + 1/64... Summing them gives Joey 2/3 and Charlie 1/3 of the total.
Measure 9 mins using 4-min and 7-min hourglasses.
Run both. When 4 ends, 3 mins are left in 7. Flip 4. When 7 ends (7m total), 1 min is left in 4. Flip 7. When 4 ends (8m total), 1 min has run into 7. Flip 7 back to get that 1m.
How many times in 24 hours do clock hands form a 90� angle?
There are 22 such instances in 12 hours (2 per hour, but reduced by overlapping positions at 3 and 9). Thus, 44 times in 24 hours.
Family has 2 kids, one is a boy. Probability the other is a girl?
The possibilities for two children are {BB, BG, GB, GG}. Knowing one is a boy eliminates GG. The remaining set is {BB, BG, GB}. Two of these have a girl: {BG, GB}.
100 people flip switches of multiples of their entry. How many stay on?
A bulb ends up 'on' if its switch is flipped an odd number of times. Only numbers with an odd number of divisors (perfect squares) satisfy this.
2 A and 2 B pills identical. Hand has 1A, 2B. How to get correct dose?
By adding another A pill, you have 2 A's and 2 B's. Cutting each in half and taking one half of each ensures you get exactly 1 A and 1 B total.
10x10x10 cube painted then cut into 1x1x1s. How many have no paint?
Removing the outer layer of cubes leaves an inner cube of dimensions (10-2)x(10-2)x(10-2), which is 8x8x8 = 512.
3-pointer (40% win) or 2-pointer (70% tie, then 50% OT win)?
Winning with a 3-pointer is 40%. For the 2-pointer, the win probability is 70% (to tie) * 50% (to win OT) = 35%. 40% > 35%.
Two men in a desert. One is dead (pack closed), one is alive (pack open).
The man died because his parachute (the 'pack') failed to open.
What is 73? chicken, 32? cat and 42? goat?
Taking parts of the words: CHI-cken, CA-t, and GO-at spells Chicago.
What English word has three consecutive double letters?
"Bookkeeper" contains oo, kk, and ee back to back, three double letters in a row.
A girl has as many brothers as sisters, but each brother has half as many brothers as sisters.
With 4 girls and 3 boys, each girl sees 3 sisters and each boy sees half as many brothers (2).
?Brothers and sisters I have none, but that man's father is my father's son.?
'My father's son' must be 'me'. So, 'That man's father is me.'
A woman shoots her husband, then holds him underwater... they enjoy a lovely dinner.
This uses darkroom photography terms like 'shooting,' 'developing,' and 'hanging' to dry.
I turn once, what is out will not get in. I turn again, what is in will not get out.
Turning a key locks or unlocks a door, controlling entry and exit.
I have a hole in my back and legs I lack. I live where I can't breathe and I eat without teeth. What am I?
A mammal with a blowhole (hole in back) and no legs.
What does man love more than life, hate more than death or mortal strife; that which contented men desire; the poor have, the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?
It's the absolute lack of anything.
I have lakes with no water, mountains with no stone and cities with no buildings. What am I?
It is a symbolic representation of the earth's surface.
With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?
An office tool that 'bites' papers to hold them together.
A man looks at a painting in a museum and says, "Brothers and sisters I have none, but that man's father is my father's son." Who is in the painting?
'My father's son' refers to the speaker himself.
The person who makes it has no need of it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?
It's a box used for burying the deceased.
I am always hungry and will die if not fed, but whatever I touch will soon turn red. What am I?
Combustion creates heat and light, consuming fuel as it goes.
What goes through cities and fields, but never moves?
It's a paved surface used for travel between locations.
What breaks yet never falls, and what falls yet never breaks?
Day 'breaks' at dawn and night 'falls' at dusk.
People make me, save me, change me, raise me. What am I?
Each verb, make, save, change, raise, is a common phrase used specifically with money.
I turn once, what is out will not get in. I turn again, what is in will not get out. What am I?
It is used to lock and unlock doors.
The more you take, the more you leave behind. What are they?
As you walk, your feet leave impressions behind on the ground.
If you drop me I'm sure to crack, but give me a smile and I'll always smile back. What am I?
A dropped mirror shatters easily, and it reflects back whatever expression, including a smile, you show it.
What can fill a room but takes up no space?
Light fills a room by illuminating it without occupying physical volume.
Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?
In very cold temperatures, the surface of the water solidifies.
What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?
A river 'runs,' has a 'mouth' where it meets the sea, a 'head' at its source, and a 'bed' along its bottom.
What is so fragile that saying its name breaks it?
The moment you speak the word "silence" aloud, you've already broken it by making a sound.
What word in the English language does the following: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?
Break the word down step by step: 'he,' 'her,' 'hero,' and finally the whole word 'heroine.'
What word is pronounced the same if you take away four of its five letters?
The letters following 'Q' are all silent in the pronunciation.
What is $3/7$ chicken, $2/3$ cat and $2/4$ goat?
Take parts of the names: Chi(cken), Ca(t), Go(at).
I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?
This riddle focuses on the literal spelling of the words mentioned.
A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?
Use simple algebra to balance the sibling relationships.
A man describes his daughters, saying, "They are all blonde, but two; all brunette but two; and all redheaded but two." How many daughters does he have?
He has one daughter of each hair color.
The day before yesterday I was 21, and next year I will be 24. When is my birthday?
The birthday falls on the very last day of the year.