Answer: 13
Althoug each round trip takes 9 minutes and can carry 5 people on the boat, you can not just divide the 20 minutes time by 9 and multiply by 5 to find the number of people that are saved without getting wet.
First trip:
5 people take the boat to the island but only 4 can stay, because one has to return with the boat to the ship to rescue other 4 people.
So, when 9 minutes have passed, 4 people are safe on the island and the boat is again by the ship.
Second trip:
In the second trip, other 4 people are rescued,along with "sailor" who returned in the boat to rescue them.
When it has passed 18 minutes, the boat is next to the ship agin to carry other 4 people before the boat sinks.
This is the last trip before the boat sinks. So, the total number of passengers rescued is 4 + 4 + 5 = 13
Answer:
P(X=3) = 0.2013
Step-by-step explanation:
After taking and tagging the first 20 birds, then we have a proportion of 20% of tagged birds within the population, that is
Supposing that the probability (0.20) of capturing a bird <em>remains constant</em>, we may resolve it as it follows:
Capturing 10 birds can be considered as a binomial experiment with a success probability p = 0.2
Let, 
be the expression of the binomial distribution, for our case we have:
p=0.2
x = 3
n=10
Then,
Therefore, the probability that exactly 3 of the 10 birds in the new sample were previously tagged is 20.13%
So basically your gonna regaurd 63.5 as 60 +3.5, 60 is 5*12 and the remaining 3.5 is less than the divisor 5, so it would be the remainder
anwser is 63.5/5 treat as 60/5+3.5/5
so anwser is 60/5+3.5/5=0.7=12.7
