a+2a+3a+4a+.+9a+10a
=(a+10a)+(2a+9a)+……+(5a+6a)
=11a+11a+11a+11a+11a
=55a
同理10b+9b+8b+.+3b+2b+b=55b
所以原式=55*11+55*1/11=610