其它
Amelia cuts a $75$ cm by $30$ cm rectangle into identical squares without any leftovers. If the length of the squares is a whole number of cm, what is the least number of squares can she get? 
Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Extracting Common Factors from Whole Numbers
75 is divisible by 1, 3, 5,15, 25 and 75.  30 is divisible by 1, 2, 3, 5\textsubscript{Z} 6,10,15 and 30.  15 is the highest common divisor for both 75 and 30.  $\textasciitilde$  To get the least number of squares, the length of the squares must be the largest possible. Hence the length must be 15 and there must be 5 x 2 = \textbf{10} squares. 