5分之24乘8分之11+10分之61除以5分之8+10分之13乘8分之11
=24/5x11/8+61/10x5/8+13/10x11/8
=(24/5+13/10)x11/8+61/10x5/8
=61/10x11/8+61/10x5/8
=61/10x(11/8+5/8)
=61/10x2
=61/5