There are 5 red pens,3 blue pens and 2 green pens in a box. Gary takes at random a pen from the box and gives the pen to his friend. Gary then takes at random another pen from the box . work out the probability that both pens are the same colour.please help
Accepted Solution
A:
♫ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ♫➷ Find the total number of pens:5 + 3 + 2 = 10The probability of taking a red the first time is 5/10The probability of taking a blue the first time is 3/10The probability of taking a green the first time is 2/10If you want to take the same colored pen again, there would be 1 less of the total pen (as it hasn't been replaced) and there would be one less of that color (as one has already been taken)Therefore:The probability of taking a red again is 4/9The probability of taking a blue again is 2/9The probability of taking a green again is 1/9Multiply the values for the same color together:5/10 x 4/9 = 20/903/10 x 2/9 = 6/902/10 x 1/9 = 2/90Add these values together:20/90 + 6/90 + 2/90 = 28/90Your answer is 28/90✽➶ Hope This Helps You!➶ Good Luck (:➶ Have A Great Day ^-^↬ ʜᴀɴɴᴀʜ ♡