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

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

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

You need to move three matchsticks to form three squares. Can you do it?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Count the number of triangles in the given picture.

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?