Eighty cards are numbered with a different number from 1 to 80. One card is removed and the numbers on the remaining cards are added. The result is a multiple of 32. Find the sum of the possible numbers that could have been on the removed card.

Guest Feb 17, 2020

edited by
Guest
Feb 17, 2020

#3**+1 **

Here's my best attempt :

sum of integers 1 - 80 = (80) (81) / 2 = 40 * 81 = 3240

Nearest integer < 3240 which is divisible by 32 = 3232

So.... the cards that could have been removed are multiples of 8 + a multiple of 32 =

8 , 40 , 72

So....the sum on these cards = 48 + 72 = 120

CPhill Feb 17, 2020