Hindi, asked by devis2awesome, 1 year ago

The houses in a row are numbered consecutively from 1 to 49.Show that there exist a value of X such that sum of numbers of houses preceeding the house numbered X is equal to sum of the umbers of houses following X. Find value of X.

Answers

Answered by delroy
8
here's your answer, HOPE IT HELPS !!!!!!!!!!!
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devis2awesome: I was kind of hoping the solution would be in regards with AP but nice try
delroy: its the unitary method
Answered by Anonymous
171

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Row houses are numbers from 1,2,3,4,5…….49.

Thus we can see the houses numbered in a row are in the form of AP.

So,

First term, a = 1

Common difference, d=1

Let us say the number of xth houses can be represented as;

Sum of preceding the numbers of x = sum of following numbers of x

i.e. Sum of ( 1,2,3,….x-1) = sum of [(x+1), (x+2) ,….48,49]

That is 1 + 2 + 3 + …… + ( x-1) = ( x+1) + ( x+2) …… + 49

 \tt => (x-1)/2[1+x-1] = (49-x)/2[x+1+49]

 \tt => (x-1)x=(49-x)(x+50)

 \tt => x²-x=49x+2450-x²-50x

 \tt => x²-x =2450-x²-x

 \tt => 2x²=2450

 \tt => x²=1225

 \tt x=√1225

 \tt x = 35

Therefore, the value of x is 35

Hope it's Helpful.....:)

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