Answer:
Expected time is 15 hours for him to get to safety.
Step-by-step explanation:
We define X as the time that this miner would get to safety.
We define Y as the door he chooses initially.
P(Y= 1) = P(Y=2)=P(Y=3) = 1/3
We have E[X|Y=1] = 3
E[X|Y] = 5 hours + E[X}
E[X|Y] = 7 hours + E[X]
Then we have
E[X] = 1/3(3 + 5 + E[X] + 7 + E[X])
We cross multiply
3*E[X] = (15 + 2E[x])
3E[X] - 2E[X] = 15
E[X] = 15
So the time it would take to get him to safety is 15 hours
Answer:
Part A: 13.2
Part B: see below
Step-by-step explanation:
<u>Part A</u>:
13.245 rounded to tenths is 13.2
<u>Part B</u>:
The rule is ...
<em>Add 1 in the number place you're rounding to if the digit to its right is 5 or more. Drop (or zero) all digits to the right of the place you're rounding to.</em>
Here, the digit to the right of the tenths place is 4, so no action is taken other than dropping digits to the right of the tenths place.
Answer: y = 20x+75
Step-by-step explanation:
Hi, to answer this question we have to write an equation:
The cost (y) must be equal to the product of the cost per hour of installation (20) and the number of hours that it takes (x); plus the fixed cost of parts and installation (75).
Mathematically speaking:
y = 20x+75
Feel free to ask for more if needed or if you did not understand something
Answer: $75 + $65w ≥ $635
Step-by-step explanation:
$635 is your goal and how much money you should earn
$75 is your already saved money
$65 is how much you're going to save every week
Ask yourself, how many weeks do you have to save money before you reach your goal of $635. Since we don't know this value, it's a variable, w.
