If price of an article decreases from Rs. 25 to Rs. 20, quantity demanded increases from Q1 units to 1500 units. If point elasticity of demand is -1.25, find Q1?
A man has some hens and some cows. If the total number of heads of hens and cows together is 50 and the nunber of feet of hens and cows together is 142, then the number of cows is