Answer:
21 minutes
Step-by-step explanation:
To cut a 5-ft log into 5 equal peices, you need to make 4 cuts (each cut cuts one piece from a whole log, the last cut divides the remaining log into two pieces).
If it takes [tex]5\dfrac{1}{4}[/tex] minutes to make one cut, then it takes
[tex]5\dfrac{1}{4}\cdot 4=\dfrac{5\cdot 4+1}{4}\cdot 4=\dfrac{21}{4}\cdot 4=21[/tex]
minutes to cut the log into 5 equal pieces.
