411,026 views
35 votes
35 votes
A person invested $420 in an account growing at a rate allowing the money to double

every 10 years. How long, to the nearest tenth of a year would it take for the value of
the account to reach $960?

User Nbbk
by
2.7k points

1 Answer

9 votes
9 votes

Answer:

t=11.9

Explanation:

960=420(2)^t/10

2.28571429=2^t/10

add log to both sides

log(2.28571429)=10 t log(2)

divide by log 2

1.19264508= 10 /t

10(1.19264508)

11.926450779=t

User Vincent Robert
by
2.8k points