julie and brandon cut lawns for their neighbors to earn money to a local charity. they thought that the customers should pay 20$. however, sevral customers offered a different pay plan and asked the students to chose. julie and brandon have to decide which of the pay plans would give them a fair deal over the long run. the customer rolls a pair of number cubes. if the product is 24 julie and brandon get 40$. otherwise, they get 10$.

User Icon for Reiny Reiny answered
14 years ago

The only way to obtain a product of 24 on 2 dice is to get a 6,4 or 4,6

prob of product of 24 = 2/36 = 1/18

expected value of that = (1/18)(40) = $2.22
expecte value of not a product of 24 = (17/18)(10) = $9.44

strange question!
where does "over the long run" come in?
What happened to the $20 charge?

User Icon for patti patti answered
14 years ago

thanks

User Icon for Explain Bot Explain Bot answered
11 months ago

To determine which pay plan would give Julie and Brandon a fair deal over the long run, we need to calculate the expected value for each pay plan.

Pay Plan 1: $40 if the product of the numbers rolled is 24, otherwise $10.

To calculate the expected value for Pay Plan 1, we need to consider all possible outcomes for rolling two number cubes and find the probability of each outcome:

Possible outcomes for rolling two number cubes:

1. Product of 24: (3, 8), (8, 3), (4, 6), (6, 4) - 4 outcomes
2. All other products: (1, 1), (1, 2), (1, 3), ..., (6, 6), excluding the ones from the first category - 36 - 4 = 32 outcomes

The probability of getting the product of 24 is 4/36 = 1/9, and the probability of getting any other product is 32/36 = 8/9.

Expected value for Pay Plan 1:
(40 * 1/9) + (10 * 8/9) = 40/9 + 80/9 = 120/9 = $13.33 (rounded to two decimal places)

Pay Plan 2: $20 regardless of the outcome.

Expected value for Pay Plan 2:
$20, since it remains constant regardless of the outcome.

Comparing the expected values for both pay plans, Pay Plan 1 has an expected value of $13.33, while Pay Plan 2 has an expected value of $20.

Therefore, to ensure a fair deal over the long run, Julie and Brandon should choose Pay Plan 2 where they earn a constant $20 per customer, regardless of the outcome of rolling the number cubes.