JEE Advance - Mathematics (1981 - No. 2)
For a biased die the probabilities for the different faces to turn up are given below :
This die tossed and you are told that either face $$1$$ or face $$2$$ has turned up. Then the probability that it is face $$1$$ is ...............
5/21
1/6
1/2
5/16
16/21