Help question 7 please
Brainliest

The answer is 5% because:
The probability of a successful outcome is (number of ways of achieving a successful outcome)/(number of ways of achieving any outcome).
The probability of first drawing blue is 4/16 = 1/4
Once a blue marble has been drawn the number of yellow marbles is unchanged (3) but the total number of marbles is now only 15. So the probability of drawing yellow is 3/15 = 1/5
The probability of drawing first blue then yellow is the product of these two results = 1/4 * 1/5 = 1/20 = 5%