SOLUTION: there are some ribbons in a box the ribbons are green or red or yellow or white the table shows each of the probabilities that a ribbon chosen at random will be green or red or whi

Algebra ->  Probability-and-statistics -> SOLUTION: there are some ribbons in a box the ribbons are green or red or yellow or white the table shows each of the probabilities that a ribbon chosen at random will be green or red or whi      Log On


   



Question 705822: there are some ribbons in a box the ribbons are green or red or yellow or white the table shows each of the probabilities that a ribbon chosen at random will be green or red or white. work out the probability that a ribbon chosen at random will be yellow. green 0.15 red 0.30 white 0.35 .so can you tell me what yellow will be and how you worked it out and also there are 500 ribbons in a box work out the number of red ribbons.much appreciated thankyou
Answer by Simnepi(216) About Me  (Show Source):
You can put this solution on YOUR website!
the total of all probabilities for choosing a ribbon must add up to 1.
because the probability of choosing a green, red or a white ribbon is
0.15 + 0.30 + 0.35 = 0.80
then the probability of choosing a yellow ribbon must be
1 - 0.80 = 0.20 or 20%
To work out the number of red ribbons that must be in the box we multiply the probability by the number of ribbons that are in the box
that is
0.30 X 500 = 150