Math
posted by Shannon on .
$100 is deposited in a savings account that pays 4% interest compounded annually.
A) how much is in the account after 5 years?
B) use logarithms to determine how many years it will take for the account to grow to $1000.
Could someone show me how to do this step by step? Thank you

a) amount = 100(1.04)^5
= ...
b)
100(1.04)^n = 1000
1.04^n = 10
log[ 1.04^n ] = log 10
n log 1.04 = 1
n = 1/log 1.04 = ...
(you do the buttonpushing)