Question – If there is a bag that has 2 balls, with the colour of the balls being unknown, what is the probability that both turn out to be blue coloured balls?
My doubt – which of the 2 following methods is correct and why :
1) Both balls can either be blue or other coloured so, 4 possibilities : (other, other), (other, blue), (blue, other), (blue, blue) hence $\frac{1}{4}$
or
2) Three possibilities : 0 blue balls, 1 blue ball or 2 blue balls as the order of balls doesn’t matter here hence $\frac{1}{3}$