(3 3/11×25.8－3 3/11×16.76+18/55×19.6)×(1.25－7/12+5/36)
=[3 3/11(25.8－16.76)+18/55×19.6]×(5/4－7/12+5/36)
=(3 3/11×9.04+18/55×19.6)×(45/36－21/36+5/36)
=(36/11×9.04+18/55×19.6)×45－21+5/36
=(180/55×9.04+18/55×19.6)×29/36
=(18/55×10×9.04+18/55×19.6)×29/36
=18/55×(10×9.04+19.6)×29/36
=18/55×(90.4+19.6)×29/36
=18/55×110×29/36
=29
3 3/11是三又十一分之三