15.
You simply multiply the ratio by the total number.
Answer:
6.6875 correct to 4 s.f
Step-by-step explanation:
T=m/f
T=120/25.6
T=6.6875 correct to 4 s.f
Answer: $15
Step-by-step explanation:
The normal price of the mirror is unknown we do not know that yet. So, let y represent the unknown number. The discount is 20 percent, we turn 20 into a decimal which would be 0.2. The amount of discount is $3. So, 0.2y equals to $3.
Then we divided.
y = 3 ÷ 0.2
And when you divide that is would be 15.
So, the regular price of the mirror is $15.
7.29 but if you have to round up, 8 days
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
