1) 2/3•6/7 = 12\21=4\7
2) 4/7•21/40 = 84\280=3\10
3) 27/32•8/9 = 216\288=3\4
4) 5/11•22/25 = 110\275=2\5
5) 8/35•5/12 = 40\420 = 2\21
