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

What has many keys but can’t open a single lock?

1 dollar = 100 cent
= 10 cent x 10 cent
= 1/10 dollar x 1/10 dollar
= 1/100 dollar
= 1 cent

=> 1 dollar = 1 cent

solve this tricky problem?

Complete the table series riddle by finding the number that can replace "??".

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

What Does this text mean:

important=important

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'