5/18 x 1/4 x 9/10
=(5/18x9/10)x1/4
=1/4x1/4
=1/16
( 1/4 + 2/9 )x 36
=1/4x36+2/9x36
=9+8
=17
7/11 x 3/8 x 4/9
=7/11x(3/8x4/9)
=7/11x1/6
=7/66