10th

what rate willl an amount double itself in 20 years at simple interest?

  1. 👍
  2. 👎
  3. 👁
  1. (1.00+x)^20 = 2 where x is the percent. If we call 1.00 + x = Y, then
    (Y)^20 = 2
    20*log(Y) = log 2
    20*log(Y) = 0.30103
    log Y = 0.30103/2 =
    Solve for y and that will tell you what 1+interest rate must be. Subtracting 1.00 will give you the interest rate. I get something like 3.5%

    1. 👍
    2. 👎
  2. In 20 years you must make one times the original amount in interest.
    20 x = 1
    x = .05 or 5%

    1. 👍
    2. 👎
  3. It said simple, not compound.

    1. 👍
    2. 👎
  4. oops. You're right. I did compound.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Finance

    Find the future value of $10,000 invested now after five years if the annual interest rate is 8 percent. a. What would be the future value if the interest rate is a simple interest rate? b. What would be the future value if the

  2. algebra

    A total of $12,000 is invested in two funds paying 9% and 11% simple interest. If the yearly interest is $1,180, how much of the $12,000 is invested at each rate? We have two unknowns: the amount of money invested at 9% and the

  3. Maths

    Mrs jasmine Invested $4000 in a building society which paid simple interest at a rate of 7.25% per annum to its investors. After 2 years, the rate was increased to 7.6% per annum. Find the amount she had T the end of 7 years

  4. math

    Yvonne put $4,000 in a savings account. At the end of 3 years, the account had earned $960 in simple interest. A. how much does she have in her account at the end of 3 years? B. at what annual simple interest rate did the account

  1. math ( grade 6 )

    review my answers and please tell me if i got them right or wrong and if I get any wrong please explain the answer to me Donna deposits $275 into her savings account. she leaves the money in her account, untouched, for 6 years. if

  2. Percentage change

    Ethan invested £500 in the bank for 2 years. He earned £40 simple interest in total. What was the simple interest rate per annum?

  3. AP Calculus AB

    Determine the amount of time it would take for an investment to double if interest is earned at a rate of 3.75% compounded continuously. Use a graph to find your answer. A. 1.85 years B. 1.93 years C. 18.48 years D. 18.83 years E.

  4. Math

    For a given interest rate, simple interest varies jointly as the principal and time. If $3000 left in an account for 6 years earned interest of $1260, then how much interest would be earned in 7 years?

  1. algebra

    A total of $6200 is deposited into two simple interest accounts. On one account the annual simple interest rate is 2%, and on the second account the annual simple interest rate is 4%. The amount of interest earned for 1 year was

  2. math

    Jamie invests $500 in an account that is compound continuously at an annual rate of 5% according to the formula A=Pe^rt, where A is the amount accrued, P is the principal, r is the rate of interest and t is the time in years.

  3. Math

    If 3000 dollars is invested in a bank account at an interest rate of 6 per cent per year, find the amount in the bank after 12 years if interest is compounded annually Find the amount in the bank after 12 years if interest is

  4. math

    a formula for calculating simple interest is I = Pr, were I is the interest earned in dollars, P is the principal or original investment, and r is the fixed rate of interest. If the amount of interest earned is $2.25 and the

You can view more similar questions or ask a new question.