Which of these explains which store has a better buy? Store C, because the ratio of the number to the cost is 6:1 in Store C and 7:1 in Store D. Store C, because the ratio of the number to the cost is 1:6 in Store C and 1:7 in Store D. Store D, because the ratio of the number to the cost is 2:14 in Store C and 3:24 in Store D. Store D, because the ratio of the number to the cost is 14:2 in Store C and 24:3 in Store D.