Ответ: 9,6
1) 18 11/13 : 10 1/24 = 245/13 : 245/24 = 245/13*24/245 сокращение 245 на 245 и получаем 1/13*1/1 =1/13
2) 2 11/13 - 1/13 = 2 10/13
3) 2 10/13:15/62 = 36/13 : 15/62 = 36/13 * 62/15 36 и 15 сокращение- 12/13 *62/5 =744/62 = 11 29/62
4) 11 29/62 -2,4 =11 29/62 - 2 4/10 = 744/62 - 24/10 = 3710/310 - 744/310= 2976/310= 9,6