1/5+1/50*10+1/10*15+1/20*25

问题描述:

1/5+1/50*10+1/10*15+1/20*25

1/5+1/50*10+1/10*15+1/20*25
=1/5+1/5+3/2+5/4
=4/20+4/20+30/20+25/20
=63/20