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A store has a parking lot which contains 70 parking spaces. Each row
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16 Oct 2017, 09:23
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78% (03:22) correct 22% (02:33) wrong based on 39 sessions
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Re: A store has a parking lot which contains 70 parking spaces. Each row
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16 Oct 2017, 10:29
Let the number of rows initially be 'n'. Since each row has same number of parking spaces, and total spaces are 70, 'n' must be a factor of 70. (option B is out)
Now, after we add 4 more rows, even if we reduce number of parking spaces per row, still every row has same number of spaces and total spaces are still 70. So 'n+4' also must be a factor of 70.
So n and n+4 both must be factors of 70. Only 10 from the given options fit the value of 'n' (because 10+4 = 14 is also a factor of 70).
So D answer



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Re: A store has a parking lot which contains 70 parking spaces. Each row
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16 Oct 2017, 10:35
We know that there are 70 spots to begin with and 70 spots to end with.
Before the new construction we have 70=x*y where x is the number of rows and y is the # of spots per row. After the construction we have 70=(x+4)*(y2).
We know that both x and y must be positive integers, so I thought the best way was to find factors of 70 that fit both equations. Factors besides 70 and 1 are 10,7, 14, 5. The only way it works is if x=10 and y=7 and we are looking to solve for x, so the answer is D.



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A store has a parking lot which contains 70 parking spaces. Each row
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23 Oct 2017, 07:18
Factors of 70= 1x70 ; 2x35 ; 5x14 ; 7x10
Now, given that one factor is reduced by 2 and other increased by 4 to retain same value, we know that 7x10 changed to (72)x(10+4) i.e. 5x14.
As number of rows increased by 4, we can deduce from above that initially there were 10 rows.
Hence, Ans D




A store has a parking lot which contains 70 parking spaces. Each row &nbs
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23 Oct 2017, 07:18






