Problem Solving

Hi All,

We're told that the architects of a certain type of building estimate construction costs to be $2.0 million per floor for each of the first 5 floors, $2.5 million per floor for each of the next 3 floors, and $3.5 million per floor for any additional floors. We're asked what the architects would estimate the construction costs to be for a building of this type with 10 floors. This question is ultimately just about Arithmetic, but since the answers are relatively 'close together', we have to be careful about doing detailed work (or we might get one of the wrong answers).

According to the given information:
Each of the first 5 floors costs $2 million each --> (5)($2 million) = $10 million
Each of the next 3 floors costs $2.5 million each --> (3)($2.5 million) = $7.5 million
Each additional floor costs $3.5 million each --> (2)($3.5million) = $7 million

Total = $10 million + $7.5 million + $7 million = $24.5 million

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorDC wrote:The architects of a certain type of building estimate construction costs to be $2.0 million per floor for each of the first 5 floors, $2.5 million per floor for each of the next 3 floors, and $3.5 million per floor for any additional floors. What would the architects estimate the construction costs to be for a building of this type with 10 floors?


A. $23.0 million

B. $23.5 million

C. $24.0 million

D. $24.5 million

E. $25.0 million


OA D

Source: GMAT Prep

For a 10-floor building, the cost is:

2.0 x 5 + 2.5 x 3 + 3.5 x 2 = 10 + 7.5 + 7 = $24.5 million.

Answer: D