Question

In a group of boys decided to send greeting cards. Each
boy sent a card to all the other boys in the group all 156 cards were sent. Find the number of boys in the group.​

Answer 1

Answer:

156 is the answer of your question

Answer 2

There are 13 boys in a group

Step-by-step explanation:

In a group of boys decided to send greeting cards. Each

boy sent a card to all the other boys in the group all 156 cards were sent.

total cards = 156 cards

let the number of students be n

then

according to the question

n(n-1) = 156

solving,

n² - n = 156

n² - n -156 = 0

n² - 13n + 12n - 156 = 0

n( n-13) + 12 ( n- 13) = 0

(n+12) (n - 13) = 0

n+12= 0

n= -12

n- 13 = 0

n= 13

number of boys can't be negative

therefore

number of boys = 13

hence ,

There are 13 boys in a group

#Learn more:

https://brainly.in/question/2619972