Algebra 1 question

With each purchase, a restaurant gives out a ticket with a number on it.  Anyone with tickets whose numbers add up to 100 wins.  A group of students collects tickets with the following numbers:  3, 3, 3, 6, 12, 15, 24, 42, 54, 60, 72, and 84.  Prove that it is impossible to form a sum of 100 from the numbers above.

所有跟帖： 

• 因為每個數都能被3整除，所以任何幾個數的和也能被3整除，但100被3除餘1 -萬斤油- ♂ (0 bytes) () 11/30/2014 postreply 08:51:43

• 謝了。 -JIAYANGGUIZI2- ♂ (0 bytes) () 11/30/2014 postreply 17:42:37