Answer:
The probability that, in successive drawing of chips, the colors of the first four chips alternate = 0.0751
Step-by-step explanation:
Step 1:
The probability that, in successive drawing of chips, the colors of the first four chips alternate, can occur in two ways: RED-WHITE-RED-WHITE (RWRW) or WHITE-RED-WHITE-RED (WRWR).
Step 2:
Given that an urn contains three white and four red chips and that each time we draw a chip, we look at its color. If it is red, we replace it along with two new red chips, and if it is white, we replace it along with three new white chips.
Probability of RWRW is given as follows:
Probabilty of the first being a red = 4/7
Probability of the next being a white = 3/9 = 1/3
Probability of the next being a red = 6/12 = 1/2
Probability of the next being a white = 6/14 = 3/7
Thus, probability of RWRW = 4/7 × 1/3 × 1/2 × 3/7 = 0.0408
Probability of WRWR is given as follows:
Probabilty of the first being a white = 3/7
Probability of the next being a white = 4/10 =2/5
Probability of the next being a red = 6/12 = 1/2
Probability of the next being a white = 6/15 = 2/5
Thus, probability of WRWR = 3/7 × 2/5 × 1/2 × 2/5 = 0.0343
Step 3:
Probability of RWRW or WRWR = 0.0408 + 0.0343 = 0.0751
Therefore, the probability that, in successive drawing of chips, the colors of the first four chips alternate = 0.0751
