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Jessica got several boxes of specialty Japanese candies as her birthday gift. She was very generous and decided to share her fortune with any friend who wanted it. Each day, she would eat two candies, and give one candy to each friend who wanted one.On the first day, one friend asked for the candy. On the second day, two asked for the candy. Each day, one more friend asked for the candy. At the end of the eleventh day, she had only one candy left, so she saved the last candy for herself to be eaten on the twelveth day. How many candies did Jessica have at the beginning?

 Jan 12, 2021
 #1
avatar+128475 
+1

11 (2)  + 1 =   23  = candies she ate

 

(1 + 2  +  ...+ 10  + 11) =   (11)(12)  / 2  =  66  = candies she gave to friends

 

23 + 66  =  

 

89  =   candies she had to  start with

 

 

cool cool cool

 Jan 12, 2021

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