so he mowed 15 out of 60, or \(\frac{15}{60} = \frac{1}{4}\) (I divided both numbers by 15)
this is equivalent to
\(\frac{1}{4}*100%=25%\)
in order to calculate the percentage,just multiply the number by 100 %, which is actually equal to 1!
so, he mowed 25 and he still needs to do 100-25=75%!!
