Index of Math Problems For math students, teachers, and enthusiasts, here's an index of the problems discussed in this book. They're organized by subject, starting with more elementary topics and progressing to more ad- vanced material. A problem followed by the symbol ``(S)'' means the solution is given in the pages listed. Otherwise, the problem is posed but not solved here--you might like to investigate such questions on your own and, if you're a teacher, assign them to your students. Geometry Altitudes of a triangle are concurrent, 87 Brahmagupta's formula for the Hero's formula for the area of a triangle, 143­146 (S) Marking volume levels on a cylindrical tank, 123­125 (S)