Solve the problem.

1) How long will it take an investment to double if it is invested at 7.8%, compounded continuously?

a) Solve the following: 31−� = 92�

b) An initial investment of $1000 is appreciated for 2 years in an account that earns 6% interest, compounded

semiannually. Find the amount of money in the account at the end of the period.

2) A company begins a radio advertising campaign in Chicago to market a new soft drink. The percentage of the

target market that buys a soft drink is estimated by the function where t is the number of days

of the campaign. After how long will 80%of the target market have bought the soft drink?

3) A certain radioactive isotope decays at a rate of 0.15% annually. Determine the half-life of this isotope, to the

nearest year.

4) The population of a small country increases according to the function where t is

measured in years. How many people will the country have after 8 years?

Find the value of the expression.

a)

Express as a single logarithm and, if possible, simplify.

b)

1 2

loga x 4loga y 3loga x

Solve the equation. Give your answer as a decimal rounded to the nearest thousandth.

c)

d)

100100 e

(.01 t )

B1900000 e

(.04 t )

lne 4

2x12

2 ln( x5 )

ln( 4 ) 1

MATH 115 Quiz 3 FA17

Solve the problem.

2) A company begins a radio advertising campaign in Chicago to market a new soft drink. The percentage of the

target market that buys a soft drink is estimated by the function where t is the number of days

of the campaign. After how long will 80%of the target market have bought the soft drink?

. a

) A certain radioactive isotope decays at a rate of 0.15% annually. Determine the half-life of this isotope, to the

nearest year

Find the value of the expression.

b)

Express as a single logarithm and, if possible, simplify.

c)

1 2

loga x 4loga y 3loga x

d)

100100 e

(.01 t )

lne 4

2 ln( x5 )

ln( 4 ) 1