SOLUTION: Ryan was 8 when his parents invested $4000 in a certificate of deposit that pays 6% for investments of 3 years. If Ryan leaves the account alone until it reaches $10,000, how old

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Ryan was 8 when his parents invested $4000 in a certificate of deposit that pays 6% for investments of 3 years. If Ryan leaves the account alone until it reaches $10,000, how old      Log On


   

Question 40880: Ryan was 8 when his parents invested $4000 in a certificate of deposit that pays 6% for investments of 3 years.
If Ryan leaves the account alone until it reaches $10,000, how old will he be?
If Ryan leaves the account alone until it doubles how old will he be?
Thank you verrryyyy much!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
If Ryan leaves the account alone until it reaches $10,000, how old will he be?
P%28a%29+=+a%28r+%2B+1%29%5Et
10000+=+4000%280.06+%2B+1%29%5Et
5%2F2+=+%280.06+%2B+1%29%5Et
log%2810%2C5%2F2%29+=+log%2810%2C%281.06%29%5Et%29
log%2810%2C5%2F2%29+=+t%2Alog%2810%2C%281.06%29%29
log%2810%2C5%2F2%29%2Flog%2810%2C%281.06%29%29+=+t
About 15.725 years .... 15 years and 9 months
Ryan would be 23 years old.
If Ryan leaves the account alone until it doubles how old will he be?
8000+=+4000%280.06+%2B+1%29%5Et
2+=+%280.06+%2B+1%29%5Et
log%2810%2C2%29+=+log%2810%2C%280.06+%2B+1%29%5Et%29
log%2810%2C2%29+=+t%2Alog%2810%2C%281.06%29%29
log%2810%2C2%29%2Flog%2810%2C%281.06%29%29=+t
About 11.896 years .... 11 years and 11 months
Ryan would be 19 years old.