The are 10 coloured balls in a bag, 4 red, 3 green, 2 orange and 1 yellow. John picks out balls and replaces them one at a time. What is the probability that the first two he picks are red?

The probability that John picks out a red ball is: The number of red balls divided by the total number of balls = 4/10
Because the balls are replaced, each event is independent so every time John picks out a ball the probability it is red is always 4/10. To determine the probability of two events both occurring we times their individual probabilities together.
Therefore the probability that the first two balls John picks out are red is: 4/10 X 4/10 = 16/100 which simplifies to 4/25

Answered by Haroon T. Maths tutor

3184 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Factorise fully 12x^2-20x+3


x^2 = 4(x – 3)^2


Solve this equation: 5x-4=3x+7


A particle is moving along a straight line. The displacement of the particle from O at time t seconds is s metres where s = 2t^3 – 12t^2 + 7t. Find an expression for the velocity of the particle at time t seconds.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences