Solution: Sharing Cards - How Many are Shared Among 20+ Children?

[Johnx1]

20 children share some cards equally. When another child joins them, they each get 2 fewer cards. How many cards are they sharing altogether?

My answer:

children = ch
cards = cd

=> cd/ch

but when another child joins them, they get 2 fewer cards. So, ch = cds - 2.

then I did cd/20(cds - 2)

Then I got stuck there for a long time.

 

[Greg]

Let the number of cards per child be x. Since 20 children are sharing the same number of cards there are 20x cards available. When another child joins them there are x - 2 cards per child. So, 20x = 21(x - 2). Can you solve that for x and use your answer to find the solution to the problem?

 

[Johnx1]

Let the number of cards per child be x. Since 20 children are sharing the same number of cards there are 20x cards available. When another child joins them there are x - 2 cards per child. So, 20x = 21(x - 2). Can you solve that for x and use your answer to find the solution to the problem?

Answer is 840. Thank you.