[tex]\displaystyle \sum_{n=1}{12} 2^n = \dfrac{(2)(1 - 2^{12})}{1 - 2} = 8190[/tex]
Answer: 8190
Jen gave 18 to Kyle so must have eaten 18.
Answer: 18
117 miles / 2.25 hours = 52 mph
Answer: 52 miles per hour
