When asked his age, a man replied that when it was divided by 2, 3, 4 or 6, there was one left over in each case. When his age was divided by 7 there was no remainder. How old was he?
He was 49 years old.
He has to be 49. When his age was divided by 7 there was no remainder. This means his age is a multiple of 7 as 7 is a prime. His age can't be 7 because 4 will yield a remainder of 3. So the next higher power 7^2 or 7×7 = 49 is the answer as 7×2, 7x3, 7x4, 7×5 and 7×6 are not an option. 49/2 = 24 + (1/2) 49/3 = 16 + (1/3) 49/4 = 12 + (1/4) 49/6 = 8 + (1/6).
In 1940, a correspondent proposed the following question:
A man's age at death was one twenty-ninth of the year of his birth. How old was he in 1900?
My house number is such that, when divided by 2, 3, 4, 5 or 6 it will always leave a remainder of 1.
However, when divided by 11 there is no remainder. What is my house number?
A man asked his neighbour’s son age. He replied in a mathematical way. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.
How old is the man’s son?
