In a society for children, each child gives gift to every other child. If the total number of gifts is 132, find the number of children.

Asked by godson babuji | 15th Mar, 2015, 02:24: AM

Expert Answer:

$L e t space t h e space n u m b e r space o f space c h i l d r e n space b e space apostrophe n apostrophe 2 cross times to the power of n C subscript 2 equals 132 rightwards double arrow 2 cross times fraction numerator n left parenthesis n minus 1 right parenthesis over denominator 2 end fraction equals 132 rightwards double arrow n squared minus n minus 132 equals 0 rightwards double arrow n squared minus 12 n plus 11 n minus 132 equals 0 rightwards double arrow n left parenthesis n minus 12 right parenthesis plus 11 left parenthesis n minus 12 right parenthesis equals 0 rightwards double arrow left parenthesis n minus 12 right parenthesis left parenthesis n plus 11 right parenthesis equals 0 therefore n equals 12 space N u m b e r space o f space c h i l d r e n space i s space 12.$

Answered by Prasenjit Paul | 15th Mar, 2015, 09:31: AM

Related Videos

This video explains the identification of series which is mathematically kn...

Problems related to the calculation of nth term in an Arithmetic progressi...

Determine the terms of an arithmetic progression when given the number of t...

This video explains the concept of the nth term and the sum of the first n ...

This video explains the identification of series, mathematically known as A...

Ask Doubt