Question

An envelope contains small strips of paper of equal size and shape. Four of the strips have the number 4 written on them, five of the strips have the number 5 written on them, and three of the strips have the number 3 written on them. What is the probability of randomly pulling a strip with the number 4 written on it followed by pulling a strip with the number 3 written on it?

Answer 1

The probability is 1/12

Explanation:

Mathematically, the probability of pulling pulling a strip with the number 4 written on it followed by pulling a strip with the number 3 written on it = Probability of pulling a strip with the number 4 written on it * Probability of pulling a strip with the number 3 written on it

The probability of pulling a strip with number 4 written on it = number of strips with number 4 written on it/total number of strips

Number of strips with number 4 = 4

Total number of strips = 3 + 4 + 5 = 12

Thus the probability = 4/12 = 1/3

The probability of pulling a strip with number 3 written on it = number of strips with number 3 written on it/total number of strips = 3/12 = 1/4

Thus , the probability of pulling pulling a strip with the number 4 written on it followed by pulling a strip with the number 3 written on it = 1/3 * 1/4 = 1/12