The radius of a circle is 10. Using π, which equation expresses the ratio of the circumference of the circle to the circle's dia
2 answers:
Answer:
Step-by-step explanation:
It is given that radius of a circle is 10.
We need to write an equation which expresses the ratio of the circumference of the circle to the circle's diameter using π.
The circumference of the circle is
where, r is the radius of the circle.
Substitute r=10 in the above formula.
Divide both sides by 20.
Therefore, required equation is .
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Lizzie has 18 dimes and 12 quarters
<em><u>Solution:</u></em>
Let "d" be the number of dimes
Let "q" be the number of quarters
We know that,
value of 1 dime = $ 0.10
value of 1 quarter = $ 0.25
Given that LIzzie has 30 coins
number of dimes + number of quarters = 30
d + q = 30 ---- eqn 1
Also given that the coins total $ 4.80
number of dimes x value of 1 dime + number of quarters x value of 1 quarter = 4.80
0.1d + 0.25q = 4.8 ------ eqn 2
Let us solve eqn 1 and eqn 2
From eqn 1,
d = 30 - q ---- eqn 3
Substitute eqn 3 in eqn 2
0.1(30 - q) + 0.25q = 4.8
3 - 0.1q + 0.25q = 4.8
0.15q = 1.8
<h3>q = 12</h3>From eqn 3,
d = 30 - 12
<h3>d = 18</h3>Thus she has 18 dimes and 12 quarters
Answer:
The population of this city in 13 years is 440,550.
Step-by-step explanation:
Given:
Suppose a city with population 300, 000 has been growing at a rate of 3% per year.
Now, to find the population of this city in 13 years.
Let the population of this city in 13 years be
Population () = 300,000.
Rate per year () = 3%.
Time () = 13 years.
Now, we put formula to get the population of the city in 13 years:
Therefore, the population of this city in 13 years is 440,550.