Online Course Discussion Forum

Math Challenge II-B combinatorics 3.22

 
 
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Re: Math Challenge II-B combinatorics 3.22
by John Lensmire - Tuesday, 21 December 2021, 12:03 PM
 

You are erasing the entire numbers, not digits. A few examples looking at the sum $1+2+3$:

  • We could erase nothing to get $1+2+3 = 6$
  • We could erase everything to get $0$
  • We could erase the $2$ to get $1+3 = 4$,
  • We could erase $2$ and $3$ to get $1$
  • etc.

Basically you're adding up some/none/all of the numbers from the original sum and trying to figure out how many different sums are possible. Hope this helps!