Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

What has one letter and starts with an E?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Who is generally closer to the kids, mom or dad?

(it's a funny riddle)