Which number should replace the question mark?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

Rearrange the letters in "new door" to make one word.

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

My sock drawer has 26 blue socks, 13 pink socks, 33 green socks, and 12 red socks, how many socks would I have to pull out in the dark to be sure I had a matching pair?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

I have Rs.50 and I spend it in the way as below.