Question

简便计算下题:1/2+1/4+1/8+1/10+1/32,1+2+3+4+5+6+5+4+3+2+1/666*666

Answer 1

1/2+1/4+1/8+1/16+1/32

=1-1/32

=31/32

(1+2+3+4+5+6+5+4+3+2+1)/666*666

=6*6/666*666

=1/111*111

=1/12321