Basket of main currencies is

(A) reference rate
(B) currency peg
(C) exchange rate
(D) special drawing rights

The answer is: (D) special drawing rights (SDR)

An isoquant is convex to the origin because of

(A) law of diminishing returns
(B) diminishing marginal rate of substitution between factors
(C) law of increasing returns

The answer is: (B) diminishing marginal rate of substitution between factors

Why the aggregate demand curve is downward sloping?

As prices fall,
(A) the demand for exports becomes more elastic
(B) fewer goods are imported
(C) the rate of interest will rise
(D) real wealth rises and so spending increases

The answer is: (D) real wealth rises and so spending increases
As prices fall, real wealth rises and so spending increases.