Here is a question out of curiosity:
What was the approximate age of Hanuman, when Bheema met him in the Mahabharata?
Age? Does one know when Hanuman was born? He was born waaay back, even before Rama. And has completed the entire Treta Yuga into Dwapara. Its impossible to track his age as we do not have a systematic calendar of those times.
Exact age of Lord Hanuman is hard to find But still we can get estimate age of Hanuman at the time when he met Bheema. Here is how...
As par this answer it's clear that Lord Rama took birth at the end of Treta yuga, So as Hanuman. As par the same answer it is also clear that Lord krishna took birth at the end of Dwapar yuga, so as Bheema.
Here 2 pints are clear that Lord Rama and Lord krishna took birth at the end of Treta yuga and Dwapar yuga respectively. Since Hanuman took birth little earlier than Rama. And Bheema was Present when Lord krishna was on earth, So that simply implies that Lord Hanuman born at the end of Treta yuga and met with Bheema at the end of Dwapar yuga Since Bheema was born at the end of Dwapar yuga.
By this calculations we conclude that age of Hanuman was nearly about (if not exact age) 1 yuga when he meet Bheema. How his age is 1 yuga? Because Hanuman born at the end of Treta yuga and met with Bheema at the end of Dwapar yuga, so....
End of Trata yuga - End of Dwapar yuga = Dwapar yuga (age of Dwapar yuga).
Hence the estimate age of Hanuman will be equal to the age of Dwapar yuga. Now to get an estimate of Hanuman's age we just need to find out age of Dwapar yuga which in not an tough task to find. Lots of info available on net about age of all yuga and here I am showing wiki's info about age of Dwapar yuga.
As par Wikipedia age of Dwapar yuga was 864,000 years. By this info we can conclude that estimate age of Hanuman at the time when he met Bheema should have been nearly about 864,000 years. As I am repeating again it is just an estimate. Exact age is not that easy to find But estimate age is not that tough to find.