The answer is 44 because all you have to do is use PEMDAS to solve the equation
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:
m^2-3m-180=0
m=15
Step-by-step explanation:
greater integer = m
small integer = n
we know that m = n+3 or n = m-3
we also know that n*m = 180
replace n for m-3
(m-3)*m=180
or
m^2-3m-180 = 0
(m-15)(m+12)=0
so m = 15 or -12, but since problem states positive, m=15
