When you flip a biased coin, the probability of getting a tail is 0.31. find the probability of getting a head

Well if the probability of getting a tail is 0.31 then the probability of getting a head must be 0.69 because 0.31 is much like 31% and the last 0.69 makes 69% resulting in the total 100% chance when combining the outcome chances seeing as a coin only has 2 sides. (Assuming we are speaking of an U.S. coin here) 

Bc equals mb that should be your answer