Ella invested $2,700 in an account paying an interest rate of 5.4% compounded monthly. Assuming no deposits or withdrawals are made, how long would it take, to
the nearest year, for the value of the account to reach $4,020?

7.4 years

Step-by-step explanation:

This is a compound interest question, from the question, we know we are to find the time.

The formula for Time in compound interest =

t = ln(A/P) / n[ln(1 + r/n)]

Where:

A = Amount after time t = $4,020

P = Principle = Initial amount invested = $2700

r = Interest rate = 5.4% = 0.054

t = ??

n = compounding frequency = monthly = 12

t = ln(A/P) / n[ln(1 + r/n)]

t = In(4020/2700)/12[In(1 + 0.054/12)]

t = 7.388 years

Approximately = 7.4 years

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500