Here are 15 math problems from the SAT that people usually get wrong — with step-by-step explanations for how to solve them.

Extra time on the math portion of the SAT helps the most able students the most.

Dread about math grid-in problems can usually be traced to misunderstandings about the question type.

A Quora thread of difficult SAT math questions included one described as the "meanest test problem ever." Can you figure it out?