One math question

Pick 3 number from the following list, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19
so that
? + ? + ? = 30.

Hint:  There is no solution in base 10 system, since odd number + odd number + odd number can not equal to even number. but if you change to different base system, must be odd base system,  like base 11, there are some solution.

My question is if high school students can understand base system concept? Myself find base system quite hard to understand for teen.
 

所有跟帖： 

• Middle schoolers who do MATHCOUNTS can easily understand base nu -BeLe- ♀ (381 bytes) () 04/27/2015 postreply 10:49:03

• +1 -BuckeyesNY- ♀ (0 bytes) () 04/27/2015 postreply 10:50:46