Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

What can go up a chimney down, but can’t go down a chimney up?

Can you solve the below tricky visual equation?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

It belongs to you, but other people use it more than you do. What is it?

What time is it when an elephant sits on a fence?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

Find the next number in the series below

21 32 54 87 131 ?

Can you identify the hidden rebus in the image below?