You have $1000 to invest in two different accounts. In order to save the money you need for college, you need to average 6.6 percent interest. If the two accounts pay 5 percent and 7 percent interest, how much should you invest in each account?
a) $500 in 5%, $500 in 7%
b) $400 in 5%, $600 in 7%
c) $200 in 5%, $800 in 7%
d) $800 in 5%, $200 in 7%

a) $500 + $525 = $ 1,025

b) $420 + $642 = $ 1,062

c) $210 + $856 =  $ 1,066

d) $840 + $214 =  $ 1,056

Step-by-step explanation:

Compound Interest Equation

A = P(1 + r/n)^nt

Where:

A = Accrued Amount (principal + interest)

P = Principal Amount

I = Interest Amount

R = Annual Nominal Interest Rate in percent

r = Annual Nominal Interest Rate as a decimal

r = R/100

t = Time Involved in years, 0.5 years is calculated as 6 months, etc.

n = number of compounding periods per unit t; at the END of each period

Compound Interest Formulas and Calculations:

Calculate Accrued Amount (Principal + Interest)

A = P(1 + r/n)^nt

Calculate Principal Amount, solve for P

P = A / (1 + r/n)^nt

Calculate rate of interest in decimal, solve for r

r = n[(A/P)^1/nt - 1]

Calculate rate of interest in percent

R = r * 100

Calculate time, solve for t

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

what's that

hey there!

if she's saving for six months, let's divide the total number we need for the trip by six, dividing it into the amount that needs to be saved for each month.

500 ÷ 6 =

she needs to save at least this amount each month, so we should use this symbol: ≥

let x be the amount she saves each month.

your final answer is x ≥

hope this !