(3/4 * 2,5 * 1 1/5) / (1 : 1/5) = (2 1/4) / 15 = 3/20 = 0,15
1) 3/4 * 2,5 = 3/4 * 2 5/10 = 3/4 * 25/10 = 3/4 * 5/2 = 15/8 = 1 7/8
2) 1 7/8 * 1 1/5 = 15/8 * 1 1/5 = 15/8 * 6/5 = 3/4 * 3 = 9/4 = 2 1/4
3) 1 : 1/15 = 15
4) (2 1/4) / 15 = (9/4) / 15 = (9*1) / (4*5) = 3 / (4*5) = 3/20 = 0,15
