Last month, sellers of good y took in $100 in total revenue on sales of 50 units of good y. this month sellers of good y raised their price and took in $120 in total revenue on sales of 40 units of good y. at the same time, the price of good x stayed the same, but sales of good x increased from 20 units to 40 units. we can conclude that goods x and y are a. substitutes, and have a cross-price elasticity of 0.60. b. complements, and have a cross-price elasticity of -0.60. c. substitutes, and have a cross-price elasticity of 1.67. d. complements, and have a cross-price elasticity of -1.67.