Answer:
<u>There were 12 gold coins in the chest at the start.</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
x = Number of gold coins in a chest
1/2x = Number of gold coins taken by the captain
1/4x = Number of gold coins taken by Sally
3 = Number of gold coins left
2. How many coins were in the chest at the start?
Let's write the following equation to solve for x:
1/2x + 1/4x + 3 = x
2x + x + 12 = 4x (Lowest Common Denominator is 4)
4x - 2x - x = 12 (Like terms)
x = 12
<u>There were 12 gold coins in the chest at the start.</u>
The answer to your question is 2.625
Answer:
The mathematical expectation of a student who purchases 10 tickets is -$39.65.
Step-by-step explanation:
A student that purchases 10 tickets out of 2900 has a probability of winning the cruise that can be calculated as:

Each ticket cost $5, so he has spent $50 for the 10 tickets.
Then, the expected value of this operation is equal to the expected value of the earnings (probability of winning the prize multiplied by the value of the prize), minus the costs:

The mathematical expectation of a student who purchases 10 tickets is -$39.65.
The answer is (4x20) + (4x4) which equals 96
Your answer is B) 1.05 x 10 5