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
Hence, the function increases at a constant multiplicative rate..
<h2>What is a function?</h2>
function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable (the dependent variable).
<h3>How to solve?</h3>
We know,
the answer is (B) the function increases at a constant multiplicative rate.
to learn more about functions: brainly.com/question/25638609
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The first car consumed 21 gallons while the second car consumed 49 gallons. here is the how it's done.
for the first car gallons consumed is 15/50x70= 21 gallons
the second car consumed 35/50x70=49 gallons
Since the variable x is at the exponent, this is an exponential function.
To decide whether an exponential function is a growing or decaying one, we have to look at the base of the exponent.
If the base is between 0 and 1, we have exponential decay
If the base is larger than 1, we have exponential growth.
In your case the base is 3, which is larger than 1, so you have exponential growth.
Thus, <u>option d</u> is your answer
