What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

What is the next number in this matchsticks series riddle?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

You bought me for dinner but never eat me. What am I?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

How many letters are in the alphabet?

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 is black when you buy it, red when you use it, and gray when you throw it away?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?