Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?
Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."
How old are the daughters?
Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?
I am an odd number. Take away a letter and I become even. What number am I?
Two friends decide to get together; so they start riding bikes towards each other. They plan to meet halfway. Each is riding at 6 MPH. They live 36 miles apart. One of them has a pet carrier pigeon and it starts flying the instant the friends start traveling. The pigeon flies back and forth at 18 MPH between the 2 friends until the friends meet.
How many miles does the pigeon travel?
A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?
In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.
If 21x = 79x, what is the value of x?
Can you find a number that lies one third of the distance between 1/3 and 2/3?
In a basket of apples,
when counted in twos, there was one extra
when counted in threes, there were two extra when counted in fours, there were three extra
when counted in fives, there were four extra
when counted in sixes, there was five extra.
However, if the apples were counted in sevens, no extra apple was left. Can you calculate the minimum number of apples that were present in the basket?
Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?
19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.