8700 dollars is placed in an account with an annual interest rate of 8%. To the nearest year, how long will it take for the account value to reach 20000 dollars?Answer:
Q. 8700 dollars is placed in an account with an annual interest rate of 8%. To the nearest year, how long will it take for the account value to reach 20000 dollars?Answer:
Identify Type of Interest: Identify the type of interest being applied.Since the problem does not specify compound or simple interest, we will assume compound interest is being applied annually.
Use Compound Interest Formula: Use the formula for compound interest to find the time.The formula for compound interest is A=P(1+r/n)(nt), where:A = the amount of money accumulated after n years, including interest.P = the principal amount (the initial amount of money).r = the annual interest rate (decimal).n = the number of times that interest is compounded per year.t = the time the money is invested for, in years.In this case, A=$20000, P=$8700, r=8% or A0, and A1 (since it's compounded annually).
Convert Rate to Decimal: Convert the percentage rate to a decimal and plug in the values.A=20000, P=8700, r=0.08, n=1.We need to solve for t.20000=8700(1+0.08/1)(1⋅t)
Simplify Equation and Solve: Simplify the equation and solve for t.20000=8700(1+0.08)t20000=8700(1.08)t
Isolate Exponential Part: Divide both sides by 8700 to isolate the exponential part.870020000=(1.08)t2.29885057471≈(1.08)t
Take Natural Logarithm: Take the natural logarithm of both sides to solve for t.ln(2.29885057471)=ln((1.08)t)ln(2.29885057471)=t⋅ln(1.08)
Divide to Solve for t: Divide both sides by ln(1.08) to solve for t.t=ln(1.08)ln(2.29885057471)t≈10.2447683516
Round to Nearest Year: Round the answer to the nearest year.t≈10 years
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