4/15乘以5/6=2/93/3乘以5/9乘以3/10=1/21/6乘以3/8乘以16=13/7乘以5/6乘以14/15=1/3
4/15x5/6=2/93/3x5/6x3/10=1/41/6x3/8x16=1/6x6=13/7x5/6x14/15=3/7x7/9=3/9=1/3
2/91/611/3
1/611/3
