8 pens in a bag, 3 blue, 5 red. 2 taken out at random, without replacement. Probability they are the same colour?

Either both blue or both red. 'OR' rule - add probabilities.Blue - first blue and second blue - 'AND' rule - multiply probabilities. 3/8 x 2/7 (as not replaced) = 6/56 = 3/28 (multiply top and bottom)Red - 5/8 x 4/7 = 20/56 = 5/143/28 + 5/14 = 3/28 + 10/28 = 13/28

Answered by Amy S. Maths tutor

2483 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

If we know that y is directly proportional to x and that when x=1, y=3, then what is the value of x when y=4?


A (0,2) and B (6,5) are points on the straight line ABCD. AB=BC=CD. Work out the co-ordinates of D.


Write (√(18)+10)/√(2) in the form: p + q√2 [4 marks]


Solve 5x + 4 = 14 + x


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