Give two reasoning for rise in demand of a foreign currrecny when its prices falls

The price elasticity of demand of good X si double the price elasticity of demand of Good Y . A 10% rise in the price of good Y results in fall in its demand by 60 units. If original demand of commodity Y was 400, calculate percentage rise in quantity demanded of good X when its when its price falls from ₹ 10 to ₹ 8 per unit.

The demand of goods x and y have equal price elaeticy. The demand of x rises from from 100 units to 200 units due to 20 % fall in its price. Calculate % rise in demand of y, if its price falls by 8%.

The price elasticity of demand of good x is half the price elasticity of demand of good y. A 25% rise in price of good y reduces its demand from 400 to 300 units. Percentage change in demand of good x when its price falls from ₹10 to ₹8 per units.