The houses of a row are numbered consecutively from 1 to 50. Show that there is value of x such that the sum of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it . Find this value of x.
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Answers
Let there be a value of x such that the sum of the number of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it
Let there be a value of x such that the sum of the number of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it House H
Let there be a value of x such that the sum of the number of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it House H3 ...H x−1 ,H xx1 ....H
....H 49
House number will form an A.P whose first term and the common difference is 1
House number will form an A.P whose first term and the common difference is 1Sum of n terms S=
⇒
⇒ 2
⇒ 2x−1
⇒ 2x−1
⇒ 2x−1 [x]=
⇒ 2x−1 [x]= 2
⇒ 2x−1 [x]= 249
⇒ 2x−1 [x]= 249
⇒ 2x−1 [x]= 249 [50]−
⇒ 2x−1 [x]= 249 [50]− 2
⇒ 2x−1 [x]= 249 [50]− 2x
⇒ 2x−1 [x]= 249 [50]− 2x
⇒ 2x−1 [x]= 249 [50]− 2x [x+1]
⇒ 2x−1 [x]= 249 [50]− 2x [x+1]
⇒ 2x−1 [x]= 249 [50]− 2x [x+1] [x−1+x+1]=
⇒ 2x−1 [x]= 249 [50]− 2x [x+1] [x−1+x+1]= [50]
⇒ 2x−1 [x]= 249 [50]− 2x [x+1] [x−1+x+1]= [50] [2x]=49×25
⇒ 2x−1 [x]= 249 [50]− 2x [x+1] [x−1+x+1]= [50] [2x]=49×25 =49×25
⇒ 2x−1 [x]= 249 [50]− 2x [x+1] [x−1+x+1]= [50] [2x]=49×25 =49×25⇒x=7×5=35.
Step-by-step explanation:
Let there be a value of x such that the sum of the number of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it
House H 1 ,H 2 ,H 3 ___.H
x−1 ,H x+1 ____H 49
House No. 1 2
3 ___x -1
x + 1.._____49
House number will form an A.P whose first term and the common difference is 1
Sum of n terms S= 2n [2a+(n−1)×d]
S x−1 =S 49 −S x⇒ 2(x−1) [2(1)+(x−1−1)1]= 249[2+48]− 2x [2(1)+(x−1)1]⇒ 2x−1 [2+(x−2)]=
249 [50]− 2x [2+x−1]⇒ 2x−1 [x]= 249
[50]− 2x [x+1]⇒ 2x [x−1+x+1]= 249 [50]
⇒ 2x [2x]=49×25
⇒x 2 =49×25
⇒x=7×5=35.
Since x is not a fraction hence the value of x satisfying the given condition exists and is equal to 35.