Ask Question
13 February, 08:27

There are 90 counters in a bag. each counter in the bag are either red or blue.

The number of red counters : The number of blue counters = 2:13

Lee is going to put some more red counters in the bag so that the probability of taking at random a red counter from the bag is 1/3. Work out the number of red counters that Lee is going to put in the bag?

+2
Answers (1)
  1. 13 February, 08:47
    0
    27 red counters must be added

    Step-by-step explanation:

    If we know that for 2 reds there are 13 blues, this adds up to 15, now, to calculate how many there are of each would be:

    90/15 = 6

    Which means that there are 2 * 6 = 12 red and 13 * 6 = 78 blue.

    Therefore, the probability that it is currently red is:

    12/90

    We need to get to 1/3, to get to this value, we must add an x quantity x:

    12 + x / 90 + x = 1/3

    3 * 12 + 3 * x = 90 + x

    3 * x - x = 90 - 36

    2 * x = 54

    x = 54/2

    x = 27

    we try:

    (12 + 27) / (90 + 27) = 39/117 = 1/3

    Therefore 27 red counters must be added
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “There are 90 counters in a bag. each counter in the bag are either red or blue. The number of red counters : The number of blue counters = ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers