Question

Calculating deposit needed You put ​$10 comma 000 in an account earning 5​%. After 3 ​years, you make another deposit into the same account. Four years later​ (that is, 7 years after your original ​$10 comma 000 ​deposit), the account balance is ​$20 comma 000. What was the amount of the deposit at the end of year 3​?

Answer 1

Amount deposited at the end of three year will be $4877.8245

Step-by-step explanation:

We have given principal amount P = $10000

Rate of return = 5 % = 0.05

First take time t = 3 years

So the amount after 3 years

`A=P(1+(r)/(100))^n=10000* (1+0.05)^3=$11576.25`

Let the amount of deposit after 3 years = x

So total amount of deposit = 11576.25 + x

Amount after 7 years = $20000

So
`20000=(11576.25+x)(1+0.05)^4`

`20000=(11576.25+x)* 1.2155`

`20000=14071+1.2155x`

`x=$4877.8245`