Question

in a group of children,each child gives a gift to every other child. If the no. gifts are 132 find the no. of children.
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ans is 12, I want the solution

Answer 1

Let there are n children, then each child will have n-1 gifts.
Total number of gift=total number of children*number of gifts per child
n(n-1)=132
solve
n can not be -ve
n=12

Answer 2

Answer:

12

Step-by-step explanation:

Let n be the number of children

Number of gifts per children = n-1 (Since no one will gift himself of herself)

Total number of gifts = $\text{No. of children} \times \text{No. of gifts per children }$

Since we are given that he no. gifts are 132

So, $132 = n(n-1)$

$132 = n^2-n$

$n^2-n-132=0$

$n^2-12n+11n-132=0$

$(n-12)(n+11)=0$

$n= 12,-11$

Since number of children can not be negative.

So, number of children is 12.