Tree is to Leaf as Flower is to ?

A. PETAL

What number should replace the question mark in the series: 12, 24, 48, ?, 192?

A. 96

In a race, five runners A, B, C, D, and E finish in the following order: A finishes before B but after C. D finishes before E but after B. What is the correct sequence of finishers?

A. C, A, B, D, E

Find the odd letter group:

D. XYZ

If A + B means A is the brother of B, and B - C means B is the sister of C, what is the relationship between A and C?

C. COUSIN