1. Fill in the blanks 1. There are no more than 50 students in a class. Group learning can be divided into three groups, four groups, six groups and eight groups according to the different teaching contents, and various assignments have just ended. There may be 48 students in this class. The greatest common factor of 2.96 and 72 is (24). Second, multiple-choice questions 1. 7×N=M, n and m are non-zero natural numbers, the greatest common factor of n and m is (b), and the smallest common multiple is (a). A.mb.n.c. 1 d.7 Third, the application question1. A 72-meter-long road originally started from one end, and there was a street lamp every 9 meters (street lamps were installed at the starting point and the end point). Now re-install, and install a lamp every 6 meters from one section. In order to save construction costs, street lamps in some locations do not need to be reinstalled. How many street lamps don't need to be reinstalled? (Draw a picture first, then answer that the street lamp is represented by 0) Solution: According to the meaning of the question, the street lamp was originally installed at 0, 9, 18, 27, 36, 45, 54, 63, 72 meters, but now it should be 0, 6, 12, 18. Liang Xiao thought: When can I play with my parents again next time? Liang Xiao knows that Mom and Dad are very busy at work, so she can only play with her when she has a rest. Dad works for 4 days and has a rest 1 day; Mom works for 3 days and has a rest 1 day; Xiaoming studies for 5 days and has a rest for 2 days (Monday to Friday). Can you help her understand? Solution: 4+ 1=5 3+ 1 =4 5+2 = 7 Find the least common multiple of 5, 4 and 7: 5x4x7 = 140 (days)140-March 25th-