Question

Peter plans to build a tree house in his back yard. He needs to know how many square feet of lumber he should buy for the floor. He considers the greatest number of people who will be in the tree house at one time, and decides to allow 20 square feet of floor space per person.
Which expression can Peter use to determine the size of the floor, in square feet, if n represents the number of people?
20n
20 + n
20 – n
20/n

Answer 1

Answer:

  20n

Step-by-step explanation:

Multiply square feet per person times the number of persons to find square feet.

The units analysis looks like this:

$\dfrac{\text{ft}^2}{\text{person}}\times \text{persons}=\text{ft}^2\\\\20\dfrac{\text{ft}^2}{\text{person}}\times n\,\text{persons}=20n\,\text{ft}^2$

Answer 2

Answer:

20n

Step-by-step explanation:

The number of square feet of floor space is given person. If n number of people will be present in the room we can convert sqaure feet per person to square feet of lumber he should buy. This can be determined by multiplying 20 sqaure feet per person by the n number of people:

$=20\cdot{n}$

The expression would therefore be 20n as the number persons cancel out at the top and bottom of the denominator and numerator to leave square feet of lumber needed.