Concept: The question tests on the basics of framing and solving equations
Let the price per unit of desks be d and that of chairs be c
Total cost of 3 desks and 1 chair= 3d + c
Total cost of 1 desk and 3 chairs = d + 3c
According to the question,
3d + c = 2(d+3c)
Total cost of 4 desks and 1 chair =4d + c = X
Total cost of 1 desk and 4 chairs = d +4c =Y
We need to find X is how many times Y??
=>X/Y = 4d + c / d + 4c
=> 4(5c) + c / 5c+ 4c
=>X/Y =7/3 = > X is 7/3 times Y (option e)
For questions on Inequalities, analyze the parts in the question stem and break them down to form an equation.