Question

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?

Answer 1

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

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