Question

A man took 3 minutes to saw a wooden plank into 4 pieces.how long will he take to saw it into 15 pieces?

Answer 1

Time taken to sew 4 pieces of wooden plank = 3 minutes
Then, time taken to sew 1 piece of wooden plank = $\frac{3}{4}$ minutes
So, time taken to sew 15 pieces of wooden plank = $\frac{3}{4}\times 15=\frac{45}{4}=11\frac{1}{4}=11+\frac{1}{4}\times 60=11\mathrm{minutes}15\mathrm{seconds}$