The income of P, Q and R are in the ratio of 5 : 4 : 3 respectively and their expenses are in the ratio of 6 : 5 : 4 respectively. If P saves Rs 4000 out of an income of Rs 10000, then what will be the saving (in Rs) of Q?
The method of soil conservation in which stones, grass, soil are used to build barriers along contours and trenches are made in front of the barriers to collect water is called?