One day, only 47 students came to practice. there were 5students marching in first row. how could the rest of students be arranged to make equal rows?

Lets solve this:-

47 - 5 = 42

42 students need to be arranged to make equal rows. 

Factors of 42:- 1, 2, 3, 6, 7, 14, 21, 42

Lets divide by each Factor:-

42 ÷ 1 = 1
1 row with 42 students 

42 ÷ 2 = 21
2 rows with 21 students each

42 ÷ 3 = 14
3 rows with 14 students each

42 ÷ 6 = 7
6 rows with 7 students each

42 ÷ 7 = 6
7 rows with 6 students each

42 ÷ 14 = 3
14 rows with 3 students each

42 ÷ 21 = 2
21 rows with 2 students each

42 ÷ 42 = 1 
42 rows with 1 student each

So, you can make 8 equal rows:-

1 row with 42 students
2 rows with 21 students each
3 rows with 14 students each
6 rows with 7 students each
7 rows with 6 students each
14 rows with 3 students each
21 rows with 2 students each
42 rows with 1 student each

Hope I helped ya!! xD

If there were 5 in the first row.  There could be 3 more rows or 14.  I hope I am understanding the question correctly.