I have $6400 to invest at 8% and 6%. What amount is to be invested at 8% in order to earn double the interest of 6%
To find out how much you need to invest at 8% in order to earn double the interest of 6%, you can follow these steps:
Step 1: Let's assume the amount to be invested at 8% is x.
Step 2: The amount to be invested at 6% would then be (6400 - x), as the total investment is $6400.
Step 3: Calculate the interest earned at 8% by multiplying the amount invested at 8%, x, with the interest rate, which is 8%. This gives 0.08x.
Step 4: Calculate the interest earned at 6% by multiplying the amount invested at 6%, (6400 - x), with the interest rate, which is 6%. This gives 0.06(6400 - x) or 384 - 0.06x.
Step 5: Since we want to find the amount to be invested at 8% that will earn double the interest of 6%, we can set up the equation:
0.08x = 2(384 - 0.06x)
Step 6: Solve the equation for x:
0.08x = 768 - 0.12x
0.08x + 0.12x = 768
0.20x = 768
x = 768 / 0.20
x = 3840
Therefore, the amount to be invested at 8% in order to earn double the interest of 6% is $3840.
To determine the amount that should be invested at 8% in order to earn double the interest of the 6% investment, you can set up an equation.
Let's say x represents the amount to be invested at 8%, and (6400 - x) represents the amount invested at 6%.
The formula to calculate interest is: Interest = Principal × Rate × Time.
For the amount invested at 8%:
Interest_8% = x × 0.08 × Time (where Time is not specified)
For the amount invested at 6%:
Interest_6% = (6400 - x) × 0.06 × Time
We want the interest earned from the 8% investment to be double the interest earned from the 6% investment:
Interest_8% = 2 × Interest_6%
Now we can set up the equation:
x × 0.08 × Time = 2 × (6400 - x) × 0.06 × Time
Simplifying the equation, we have:
0.08x = 2 × 0.06 × (6400 - x)
0.08x = 0.12 × (6400 - x)
Now, we can solve for x:
0.08x = 768 - 0.12x
0.08x + 0.12x = 768
0.2x = 768
x = 768 / 0.2
x = 3840
Therefore, $3,840 should be invested at 8% in order to earn double the interest of the amount invested at 6%.
Let x be the amount invested at 8%.
6400-x = amount invested at 6%.
Assuming simple interest, or invested for a short time, then
x*8% = 2(6400-x)*6%
Solve for x.
x = amount invested at 6%
y = amount invested at 8%
0.06x = interest at 0.06
0.08y = interest at 0.08
Solve simultaneously,
x + y = 6400
0.08y = 2(0.06x)
x = $2560
y = $3840
$153.60 = 6% int
$307.20 = 8% int