How many rectangular tiles are required for the kitchen floor?

Question

(1) Each tile is 48 square inches.
(2) The kitchen measures 10 feet by 7 feet.

deepthiraghav · Answer

Both statements are required but neither one of them alone will be sufficient

MathRevolution · Answer

Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

How many rectangular tiles are required for the kitchen floor?

(1) Each tile is 48 square inches.
(2) The kitchen measures 10 feet by 7 feet.

In the original condition, length and width of the kitchen floor and the tiles are unknown, in which there are 4 variables, which should match with the number of equations. So you need 4 variables. For 1) 1 equation, for 2) 1 equation, which is likely to me E the answer. 
When 1) & 2), even if the area of each tile is 48 square inches, you cannot figure out the length and the width, which is not sufficient. 
Therefore, the answer is E.

-> For cases where we need 3 more equations, such as original conditions with “3 variables”, or “4 variables and 1 equation”, or “5 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 80% chance that E is the answer (especially about 90% of 2 by 2 questions where there are more than 3 variables), while C has 15% chance. These two are the majority. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since E is most likely to be the answer using 1) and 2) separately according to DS definition (It saves us time). Obviously there may be cases where the answer is A, B, C or D.

GMATinsight · Answer

Question  : No. of rectangles required = ? (We need dimension of tile and floor of kitchen to answer this

Statement 1 : Each tile is 48 square inches.

Area of the Kitchen floor (alongwith the dimensions of Kitchen floor and tile) is not available so 
NOT SUFFICIENT

Statement 2 : The kitchen measures 10 feet by 7 feet.

Area of the Kitchen floor = 70 sq.ft but area of the tiles (alongwith the dimensions of the tile) is not available so 
NOT SUFFICIENT

Combining the two statements

Dimensions of Rectangular tiles are not available hence
NOT SUFFICIENT

Answer: Option E

P.S.  USUAL MISTAKE, No. of tiles = Area of Kitchen floor / Area of Tile 
 
CORRECT WAY OF SOLVING,
No. of Tiles needed along LENGTH of floor = Length of Kitchen Floor / Length of Tile
and 
No. of Tiles needed along WIDTH of floor = Width of Kitchen Floor / Width of Tile

No. of tiles needed = No. of tiles on length * No. of Tiles on width

hwgmat2015 · Answer

I think the catch here is 48 square  inches . If inches would have been feet then only one option fits in 8*6=48

So E.

GMATinsight · Answer

Hi  hwgmat2015

Let me bring in your notice that NOWHERE it has been mentioned that dimensions are in INTEGERS whether it's feet or inches..

SO better avoid such mistakes.

The best way to avoid such mistakes is to remain critical.

P.S. Don't only look at Given information, Please think of information that is not given in order to avoid unwanted natural assumption

hwgmat2015 · Answer

How the answer can be C ? 
Any takers?

How many rectangular tiles are required for the kitchen floor?

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