Question

1/2+5/6+11/12+19/20 这道题怎么简便运算

Answer 1

1/2+5/6+11/12+19/20

=(1-1/2)+(1-1/6)+(1-1/12)+(1-1/20)

=4-(1/2+1/6+1/12+1/20)

=4-(1/2+1/2-1/3+1/3-1/4+1/4-1/5)

=4-(1-1/5)

=4-4/5

=3又1/5（16/5）