A Group of 630 Children is Arranged in Rows for a Group Photograph Session. Each Row Contains Three Fewer Children than the Row in Front of It What Number of Rows is Not Possible? - Mathematics


A group of 630 children is arranged in rows for a group photograph session. Each row contains three fewer children than the row in front of it. What number of rows is not possible?


  • 3

  • 4

  • 5

  • 6





Let no of children be x, x + 3, x + 6, x + 9, x + 12, x + 15......

Present in Rows R1 ,R2, R3, R4, R5, R6 ....... respectively Putting R = 3, 4, 5 and 6

We see that when R = 6

x + x + 3 + x + 6 + x + 9 + x + 12 + x + 15 = 630

6x + 45 = 630

6x = 585

x = 97.5

then x is not an integer.

So R = 6 does not satisfies.

Concept: Permutation and Combination (Entrance Exam)
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2014-2015 (May) Set 1


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