For how many integer values of M is M/30 strictly between 1/3 and 5/3?
7 intgers 11,12,13 ,14 ,15 ,16 ,17
1/3 < M/30 < 5/3
1/3 < M /30 and M/30 < 5/3
30 (1/3) < M M < (30) (5/3)
M > 10 M < 50
Number of integers = (49 - 11) + 1 = 39
