Question

If the coin removed is blue, what is the probability of drawing a red coin after three red coins are put in the bag to replace the blue one? The probability of drawing a red coin after three red coins are put in the bag to replace the blue one that has been removed is

Answer 1

This question cannot be answered with the details provided. How many coins are there to start with? Probability works by taking favorable outcomes divided by total outcomes. Without the total number of either, any question like this is impossible to solve.