Rachel invested $15,000 in a nine-year cd giving 8.5% interest, but needed to withdraw $4,000 after two years. if the cd's penalty for withdrawal was six months' worth of interest on the amount withdrawn, how much money did rachel have when the cd reached maturity, not including the amount she withdrew? round answer to the nearest whole dollar

Given:
principal 15,000
term 9 years
rate 8.5%

Interest = Principal * Interest Rate * Term
I = 15,000 * 8.5% * 9
I = 11,475

Total = 15,000 + 11,475 = 26,475 on date of maturity

Interest = 15,000 * 8.5% * 2
I = 2,550

Total = 15,000 + 2,550 = 17,550

amount withdrawn = 4,000 

Penalty = 4,000 * 8.5 % * 6/12
P = 170

Net amount = 17,550 - 4,000 - 170 = 13,380

I = 13,380 * 8.5% * (8-2)
I = 6,823.80

Total = 13,380 + 6,823.80 = 20,203.80 total amount on maturity.