Chapter 11 - Review - Page 667: 27

512 dollars saved on day 10 536,870,912 dollars saved on day 30

1 dollar, day 1 2 dollars, day 2 4 dollars, day 3 $4/2=2$ $2/1=2$ Common ratio is 2 $a_n = 2^{n-1}$ $n=10$ $a_10=2^{10-1}$ $a_10=2^9$ $a_10 = 512$ 512 dollars saved on day 10 $n=30$ $a_30=2^{30-1}$ $a_30=2^{29}$ $a_30 = 536,870,912$ 536,870,912 dollars saved on day 30