Since, it is not given how many coins did Erica buy at the coin show, so, we can suppose that Erica bought "n" coins from the coin show.
Now, we know that Erica already had 6 coins in her coin collection before she went to the coin show and bought the "n" coins.
Therefore, the total number of coins that Erica will have in her possession after buying "n" coins from the coin show will be 6+n.
The answer is D. I’m assuming this is surface area so here’s my explanation:) ok so the area of the triangle is 6 (4x3 divided by 2) and when you add the other triangle that’s 12. Ok so we have 12 so far. Then the area of the bottom rectangle is 24 (3x8). Then the area of the side rectangle is 32 (4x8). THEN the top rectangle’s area is 40 (8x5). When you add the numbers up (12+24+32+40) you get 108! And of course dont forget the cm2. ( centimeters squared ). :) I hope this helps
Answer
a. True
Step-by-step explanation:
Based on this survey we estimate that about 
of the college students smokes. And a 
confidence interval is ![[15.1\% ; 21.6\%]](https://tex.z-dn.net/?f=%5B15.1%5C%25%20%3B%2021.6%5C%25%5D)
. So we know that 
our estimative for the smoking rate is in the confidence interval with certainty. We also know the estimative for the smoking rate in the general population is 
. So we can write the two possible hypothesis:
Smoking rate is equal to .
Smoking rate is not equal to .
We will reject the null hypothesis 
if the estimate doesn't fall into the confidence interval for the college students smoking rate.
Since this condition holds we reject the null hypothesis. So with certainty we say that the smoking rate for the general population is different than the smoking rate for the college students.
As shown in the figure
Height of helicopter above the ground=30 m
Distance from the base to the point where the person is standing=30 m
height of the person=2 m
Now the person cast the shadow of length x m.
Triangle ABC and triangle EDC are similar.
∵ ∠B= ∠D=90°
∠C is common.
So by AA similarity ΔABC and ΔEDC are similar.
As we know when triangles are similar their sides are proportional.
AB/AD =BC/DC
Let DC=x meter
⇒
⇒5=\frac{30+x}{x}[/tex]
⇒5x=30+x
⇒4x = 30
⇒ x=30/4
⇒ x=7.5 meter
So length of shadow=7.5 meter
2. volume of a sphere of radius r is v (r) =
=4/3π×3
=4π
surface area of a sphere of radius r is 4π
b) Ratio of derivative of volume of sphere to surface area of sphere=
=1 [ incomplete question but you have written few words ]
