A leprechaun places a magic penny under a girl's pillow. The next night there are 2 magic pennies under her pillow. Each night the number of magic pennies doubles. How much money will the girl have after 22 nights?

tn = 2097152 pennies tn = 20971.52 dollars.

Step-by-step explanation:

A surprisingly large amount of money.

The question is "Does the amount of money just double or do the previous amounts add to the present amount?"

I think it just doubles. Not only that, but she can't spend any of it until night 22 is reached.

tn = a*2^ (n - 1) a = 1 She starts with 1 penny. n = 22 tn = 1*2^ (22 - 1) tn = 1*2^21 tn = 2097152 pennies tn = 20971.52 dollars.