2/3x5/8x1/3
=1/3*5/4*1/3
=5/36
(5/13x3/4)x(13/5x12)
=5/13*13/5*3/4*12
=1*9
=9
(3/5+3/8)x5x8
=3/5*5*8+3/8*5*8
=24+15
=39