Question

A ship must have 1 lifeboat for every 12 passengers, plus one lifeboat for
the crew and one backup lifeboat. Which equation shows the
relationship between the number of passengers, p, and the number of
lifeboats needed, I?

Select one

1) I= 2 + 1/2
2) I= 2p + 10
3) I= 12p
4)I=2+ p/12

Answer 1

Answer: Choice (4)  L = 2 + p/12

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Explanation:

p = number of passengers

L = number of lifeboats

Since we're grouping the passengers in groups of 12, this strongly implies we'll be dividing two values. Specifically we have p divided by 12 to represent the number of boats we will need just for the passengers.

For example, let's say p = 36. This means we have 36 passengers. That would mean we need p/12 = 36/12 = 3 boats for those 36 passengers. This excludes the crew and backup boat. Adding those two extra boats leads to the expression 2 + p/12 which is the total number of lifeboats needed.

In the event that p is not a multiple of 12, this leads to p/12 not being a whole number. We could have say p = 50 passengers which means p/12 = 50/12 = 4.167 approximately. We will not round this to 4 because then we'll have passengers without a lifeboat.

We must round 4.167 up to the nearest whole number to get 5. The first four boats take care of 4*12 = 48 passengers, while that 5th boat handles the remaining 50-48 = 2 people. Since 2 people in a boat seems like a really low count, the crew could likely spread the people out such that say 10 people would be in each boat (since 50/10 = 5).

So in short, the result of p/12 is rounded up to the nearest whole number.