Tools help us d do work with less _________

Tools used to make article or to repair them are called _________

Select the correct option which best suits the given descriptions for P, Q, R and S. P - A simple tool used for removing weeds. Q - A tool that is used for ploughing the field. R- A tool that is used for sowing with the help of tractor. S - A simple tool used for cutting of crops.

G is twice as fast as S in doing work. If G can do a work in 30 days less than S, how many days will they take to complete the work together?

Identify the tool which used for cleaning water helps clear the turbidity of water?