An industrial water treatment plant produces sludge with a moisture content of 97%. With the solid content remaining constant, the sludge is thickened so that the moisture content reduces to 94%. If the original quantity of sludge is P, estimate the quantity of the thickened sludge.

The average price of 'n' liters of synthetic oil is Rs. 90 per liter. When 10 liters of synthetic oil with a price of Rs. 60 per liter is added to it, the average price of the mixture becomes Rs. 70 per liter. What is the value of 'n'?

In a zoo, there are horses and pigeons. If heads are counted, there are 340 heads, and if legs are counted, there are 1060 legs. How many pigeons are there?