The cost of a pair of ice skates went from $200 to $140. What is the percent change in the cost of skates?

Mathematics

1 answer:

dmitriy555 [2]3 years ago

3 0

so the pair went down from 200 to 140, so the difference is 200 - 140 = 60.

so if we take 200 as the 100%, what is 60 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 200&100\\ 60&x \end{array}\implies \cfrac{200}{60}=\cfrac{100}{x}\implies \cfrac{10}{3}=\cfrac{100}{x}\implies 10x=300 \\\\\\ x = \cfrac{300}{10}\implies x = 30$

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90 points please help!!!!!!!!

just olya [345]

To model this situation, we are going to use the exponential function: $f(t)=P(1+ \frac{r}{n} )^{nt}$
where
$P$ is the initial number of cars
$r$ is the growing rate in decimal form
$n$ is number of tames the growing rate is increasing per year
$t$ is the time in years

To convert the growing rate to decimal form, we are going to divide the rate by 100%
$r= \frac{12}{100}$
$r=0.12$
Since the growing rate is increasing quarterly, $n=4$ . We also know that the initial number of cars is 920, so $P=920$ . Lets replace all those values in our function:
$f(t)=920(1+ \frac{0.12}{4} )^{4t}$
$f(t)=920(1+0.03)^{4t}$
$f(t)=900(1.03)^{4t}$

We can conclude that:
Rate ---------> The quarterly rate of growth is 0.03 or 3%
Exponent --------> The compound periods multiplied by the number of years is 4t
Coefficient--------> The initial number of cars serviced is 920
Base------> The growth factor is represented by 1.03

3 0

3 years ago

Read 2 more answers

Ginny is studying a population of frogs. She determines that the population is decreasing at an average rate of 3% per year. Whe

svp [43]

Answer:

Step-by-step explanation:

This is exponential, of the form

$y=a(b)^x$ where a is the initial amount and b is the growth/decay rate. If Ginny begins the study with 1200 frogs in the population, our a value is 1200.