Conditional Probability

Question

A piggy bank contains 4 Quarters, 3 dimes and 2 nickels. Two coins are taken out of the piggy bank, one after the other without replacement. Find the conditional probability that the first coin removed was a quarter given that the last coin removed was a nickel.

Answer 1

P(FQ|LN) = 4/8 = 1/2 = 0.5, because if last nickel, then total 8 coins and 4 quarters there

Answer 2

if 2nd coin was a nickel, that leaves 8 possible outcomes for the 1st coin with 4 as quarters. 4/8 = 1/2 = 50% chance the 1st coin is a quarter P(Q1/N2) = 0.5