Bunuel wrote:

Monthly rent for units in a certain apartment building is determined by the formula \(k*\frac{5r^2+10t}{f+5}\) where k is a constant, r and t are the number of bedrooms and bathrooms in the unit, respectively, and f is the floor number of the unit. A 2-bedroom, 2-bathroom unit on the first floor is going for $800/month. How much is the monthly rent on a 3-bedroom unit with 1 bathroom on the 3rd floor?

(A) $825

(B) $875

(C) $900

(D) $925

(E) $1,000

As we're given all the data we need and just need to plug things in, we'll jump straight into the calculation.

This is a Precise approach.

Since r = 2, t = 2, f = 1 give a rent of 800, then plugging in the numbers gives

800 = k * (5*4 + 20)/(1+5) --> 800 = 40k/6 --> 20 = k/6 --> k = 120

So, if r = 3, t = 1, and f = 3 then the rent is

120(5*9+10)/(3+5) = 120*55/8 = 15*55 = 550 + 275 = 825

(A) is our answer.

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