The difference between Charles' and Shriya's ages is 6 years. When they married each other 30 years ago, 4 times Charle's age was the same as 5 times the age of Shriya. What is the current sum of their ages?
If price of an article decreases from Rs 40 to Rs 30, quantity demanded increases from Q1 units to 7500 units. If point elasticity of demand is -1 find Q1?