Question 15: What does the notation (A extrm U B)' represent? Question 16: If 45% use bus, 30% bicycle, 25% walk, 10% bus & bicycle, 8% bicycle & walk, 12% bus & walk, and 2% all three, what percentag

You're on a roll — 15. C. Outside both A and B The notation (A B)' represents the complement of the union of sets A and B. The union A B includes all elements that are in set A, or in set B, or in both. The complement (A B)' therefore includes all elements that are not* in A B. This means elements that are neither in A nor in B, which corresponds to the region outside both A and B in a Venn diagram. 16. A. 25% Let B represent students who use the bus, C for bicycle, and W for walk. We are given the following percentages: n(B) = 45\% n(C) = 30\% n(W) = 25\% n(B C) = 10\% (bus and bicycle) n(C W) = 8\% (bicycle and walk) n(B W) = 12\% (bus and walk) n(B C W) = 2\% (all three modes) To find the percentage of students who use only the bus, we use the formula: n(B only) = n(B) - n(B C) - n(B W) + n(B C W) Step 1: Substitute the given percentages into the formula. n(B only) = 45\% - 10\% - 12\% + 2\% Step 2: Perform the subtraction and addition. n(B only) = 35\% - 12\% + 2\% n(B only) = 23\% + 2\% n(B only) = 25\% Therefore, 25% of students use only the bus. The final answer is A. Got more? Send 'em!