42.
In a free economy the national income is Y (C, I, G, X, M) means consumption, investment, government expenditure and total exports and total imports respectively

44.
Relation between AR, MR and elasticity of demand can be established by the formula

45.
The indifference curves show-

46.
When a perfectly competitive industry is in long-run equilibrium, all firms in the industry

49.
Gossen's second law states that