She too got a math question and she too was a nervous wreck. Lucky for her, her phone a friend figured it out immediately and Wynona won $50K for her charity. She also gave the studio audience a copy of her new CD which is a collection of very old standards, think Nat King Cole.
Maybe that's the reason they give them math questions. The network doesn't just want to dole out $50K without somewhat of a struggle. They don't want to make it TOO easy.