Question

A model deck is `9 i n`. by `16 i n`. How do you use the scale `1/2 i n : 1 ft` to find the dimensions of the actual deck?

Answer 1

`18 " ft" xx 32 " ft"`

Explanation:

Given: model is `9 " in" xx 16 " in"; " scale" = 1/2 " in": 1 " ft"`

You can set up two proportions to solve this problem:

`(9 " in")/(.5 " in") = (x " ft")/(1 " ft")`

`(16 " in")/(.5 " in") = (y " ft")/(1 " ft")`

Use the cross-product to solve `a/b = c/d; " "ad = bc`

`.5x = 9; " "x = 9/.5 = 9*2 = 18 " ft"`

`.5y = 16; " "y = 16/.5 = 16*2 = 32 " ft"`