We have two urns. the first urn contains two balls labeled 1 and 2. the second urn contains three balls labeled 3, 4, and 5. we choose one of the two urns at random with equal probability and then sample one ball, uniformly at random, from the chosen urn. what is the probability that we picked the ball labeled 5

The probability of randomly picking a ball labeled 5 from the urn is 1/6

Recall :

Number of urns = 2

Probability of selecting urn 2 :

Ball labels in urn 2 = 3, 4, 5

Probability of picking a ball labeled 5 from urn 2 :

Therefore, the probability of selecting a ball labeled 5 is :

Learn more :link

The probability of picking the urn with the number 5 in it is 1 out of 2, which is written as 1/2.

The probability if picking the number 5 out of that urn would be 1 out of 3 , written as 1/3.

The probability of both is found by multiplying the two probabilities together:

1/2 x 1/5 = 1/10 probability.

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!