Question

Benjamin​ & Associates, a real estate​ developer, recently built 200 condominiums in​ McCall, Idaho. The condos were either three​-bedroom units or four​-bedroom units. If the total number of rooms in the entire complex is 712​, how many three​-bedroom units are​ there? How many four​-bedroom units are​ there? There are nothing three​-bedroom units and nothing four​-bedroom units.

Answer 1

Answer: There are 88 three bedroom units and 112 four bedroom units.

Explanation:

Let x be the number of three​-bedroom units and y be the number of four​-bedroom units.

Then, we have the following system of equations :-

`x+y=200------(1)\\\\3x+4y=712--------(2)`

Multiply 4 on both sides of the equation(1), we get

`4x+4y=800-----(3)`

Eliminate (2) from (3)

`x=88`

Put x=88 in (1), we get

`88+y=200\\\\\Rightarrow\ y=200-88=112`

Hence, there are 88 three bedroom units and 112 four bedroom units.