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?

By adding four matchsticks, can you divide the square shown in the picture into two equal parts?

You are provided with a grid (as shown in the picture). Can you fill the squares with numbers 1-8 in a manner that none of the two consecutive numbers are placed next to each other in any direction (vertically, horizontally or diagonally?)

You need to remove four matchsticks from the picture below and still need to maintain the following as in the original image.
1. 1st row contains 12 matchsticks
2. 2nd row contains 12 matchsticks
3. 1st column contains 12 matchsticks
4. 2nd column contains 12 matchsticks

There was a strange boy who was born before his father. How can this be possible?

Through your logical capabilities, can you make 7 an even?

If 21x = 79x, what is the value of x?

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

You can see three almost identical images below. Can you spot the odd one out from them?

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