8k8
+ k88
--------
1,6r6
If k and r represent non-zero digits within the integers above, what is r?	Choose one
A) 6	B) 7	C) 8	D) 9	E) 17
8k8   k88   --------   16r6   Trial and error or just plug-in method might be the shortest way to solve this problem. Though you can narrow down the possible values of k to just two: 7 and 8 --&gt; 8**+7**=16** or 8**+8**=16** (k can not be less than 7 or 9, as the result won't be 16**). After that it's easy to get that k=7 and r=6.   6nswer: 6.
<result>A</result>
8k8
+ k88
--------
1,6r6
If k and r represent non-zero digits within the integers above, what is r?