Qxd = 1,950 - 200 PX - 50 PY + 2 R or : Qxd: quantity requested of good X; PX: price of good X; PY: price of good Y; A: consumer income. 2.1 If R = $ 250 and PY = $ 5, then the price at which consumers will stop buying this product is: a) $ 12; b) $ 11; c) $ 10; d) $ 9. 2.2 For the same values of R and PY (see number 2.1), the price that would allow the 1000 available units of this product to be sold would be: a) $ 6; b) $ 4.50; c) $ 4; d) $ 3.50. 2.3 If now PY increases by $ 2 (all other things being equal), then there will be on this market: a) a surplus of 100 units; b) a surplus of 50 units; c) a shortage of 100 units; d) a shortage of 50 units. 2.4 What must now be the variation in the price of good X to bring the quantity demanded to 1000 units? : (a) an increase of $ 0.50; b) a decrease of $ 2; c) a decrease of $ 1; d) a decrease of $ 0.50