Assuming simple interest (i.e. no compounding within first year), then
At 6%, interest = 10000*0.06=$600
At 9% interest = 10000*0.09 = $900
Two ways to find the ratio
method A. let x=proportion at 6%
then
600x+900(1-x)=684
Expand and solve
300x=900-684=216
x=216/300=0.72 or 72%
So 10000*0.72=7200 were invested at 6%
10000-7200=2800 were invested at 9%
method B: by proportions
Ratio of investments at 6% and 9%
= 900-684 : 684-600
=216 : 84
= 18 : 7
Amount invested at 6% = 18/(18+7) * 10000 = 0.72*10000 = 7200
Amount invested at 8% = 7/(18+7)*10000=0.28*10000=2800
What if I write the equation like this:
y = zero x - 3.
Now you know that the slope of the line is zero and its y-intercept is -3.
That's a horizontal line that crosses the y-axis at -3. And just like the equation says, the value of 'y' doesn't depend on 'x'. It's -3 everywhere.
Answer: 6.8%
Step-by-step explanation:
We need to find both percentage so we can determine the increase.
Finding percentage of $10 return: 1% return
Finding percentage of $78 return: 7.8% return
To find the percent increase we do 7.8%-1.0% = 6.8%
