А) 1 1/5•1/6; б) 2 2/5•2/3; в)7/9•4 1/2; г) 3/7•3 1/3; д)11/2•1 1/3; е) 2 1/2•1 3/5; ж)72/3•2 1/4; з) 5 2/5•1 1/9.

а) 1 1/5•1/6 = 6/5*1/6 = 1/5;
б) 2 2/5•2/3 = 12/5*2/3 = 8/5 = 1 3/5;
в) 7/9•4 1/2 = 7/9*9/2 = 7/2 = 3 1/2;
г) 3/7•3 1/3 = 3/7*10/3 = 10/7 = 1 3/7;
д)11/2•1 1/3 = 11/2*4/3 = 22/3 = 7 1/3;
е) 2 1/2•1 3/5 = 5/2*8/5 = 8/2 = 4;
ж) 7 2/3•2 1/4 = 23/3*9/4 = 69/4 =  17 1/4;
з) 5 2/5•1 1/9 = 27/5*10/9 = 2*3 = 6.