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?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

What does the below rebus puzzle mean?

With the help clues provided in the image, can you find the 5 digit key?

In an interview, a boy was asked an unusual question 'How two persons sitting with a table in between them can't see each other?' He was unable to reply. Can you?

Can you find any error in the following sentence?

A taxi was standing outside a fort at night. A man came out of the fort, opened the gate and hit the taxi driver killing him instantly. He took all the money out of the meter and started running till he was caught by a local sheriff.

If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

what one word does the below rebus identifies?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.