A 4 digit number 8a43 is added to another 4 digit number 3121 to give a 5 digit number 11b64, which is divisible by 11, then (a+b)=?	Choose the correct choice from the following answers:
A) 3 B) 4 C) 7 D) 5 E) 9
Solution: a+1=b   =&gt; b-a=1.   and 11b64 is divisible by 11   =&gt; (4+b+1)-(6+1)=0   =&gt; b-2=0   =&gt; b=2.   so, a=1   =&gt;(a+b)= 3.   3nswer 3
<result>A</result>
A 4 digit number 8a43 is added to another 4 digit number 3121 to give a 5 digit number 11b64, which is divisible by 11, then (a+b)=?