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

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

Which is faster, Heat or Cold ? Explain.

John buys rice at Rs.60/kg from Britain and then sells them at Rs.5/kg in India. As a result of this, he becomes a millionaire. How come?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

What does this below rebus puzzle mean?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Can you spot the man between the coffee bean in the picture below ?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?