The probability of drawing a blue marble out a bag
⇒ is the number of blue marbles over the total number of marbles in
the bag
However, since one blue marble was already drawn out
⇒ we must minus one from the total blue marbles
⇒we must also minus one from the total marble
Thus the probability is
[tex]\frac{Number-of-Blue-Marbles}{Total-Number-of-Marbes} =\frac{2}{5}[/tex]
Answer: 2/5
Hope that helps!