十八分之五×四分之一×十分之九
=5/18x9/10x1/4
=1/4x1/4
=1/16
(四分之一+九分之二)×36
=1/4x36+2/9x36
=9+8
=17
十一分之七 ×八分之三×九分之四
=7/11x1/6
=7/66