Mom's Riddle

My mother, age 92 living an an assisted living residence in Plano, TX, told this "riddle" to me and Pam--really just a joke circulating at the place: "If you had the choice of taking $100,000 now or waiting 31 days for the amount equal to a penny compounding 100% everyday for 31 days, which would you pick?" I after a long pause: "I need to get out my slide rule." Pam: "I'd wait 30 days." Mom, looking at my knit brow in calculation: "Don't try to figure it. You can't." I: "Okay, I'll take the hundred thousand now." Mom: "I took the 31 days [wry smile]. I'm a gambler." Pam: "So what's the answer?" Mom: "Thirty one days. You'd have 100 million." Mom, wry smile: " I'm 92 years old. I'd take the hundred thousand now. I don't know if I'll be around in 31 days."