The answer is C.
∠STR = ∠SRQ = 90° (given) (A)
∠RST = ∠RSQ (common angle) (A)
By AA test for similarity,
∆STR is similar to ∆SRQ.
This problem can be solved by the chicken rabbits method or you can just do simple algebra.
I.) Chicken and rabbits method
First assume all 110 coins are dimes and none are quarters.
We will have a total value of 11 dollars
Now for each dime we switch out for a quarter, we adds 15 cents to the total value.
18.50-11=7.50 dollars
There are 750/15=50 group of 15 cents in the 7 dollars and 50 cents.
This also meant that we need to switch out 50 dimes for 50 quarters.
So we have 50 quarters.
That first method is very good and very quick once you get the hang of it, now I'm going to show you the algebraic way to solve this.
Let's say there are x dimes and y quarters.
Set up equation
x+y=110
10x+25y=1850
Now solve multiply first equation by 10
10x+10y=1100
subtract
15y=750
y=50
Now we set the numbers of quarters to y so the answer is 50 quarters.
I personally recommend using algebra whenever you can because the practice is very important and you will eventually get really fast at setting up and solving equations. The first method is faster in this case but the second is more generalize, hope it helps.
Answer:
880 high-quality version
Step-by-step explanation:
I think the below is your full question:
<em>A Web music store offers two versions of a popular song. The size of the standard version is 2.1megabytes (MB). The size of the high-quality version is 4.5 MB. Yesterday, there were 1290 downloads of the song, for a total download size of 4821 MB. How many downloads of the high-quality version were there?</em>
Here is my answer:
Let x is the number of high-quality version
So the number of standard version= 1290 - x
We also know: total download size of 4821 MB. which means:
4.5x + 2.1(1290-x) = 4821
<=> 4.5x+2709-2.1x=4821
<=> 2.4x=2112
<=> x=880
So there were 880 high-quality version
The difference (the answer of a subtraction problem) is:
2/7 - 2/5 --> 10/35 - 14/35 = -4/35
The answer sum (the answer of an addition problem) is:
2/7 + 2/5 --> 10/35 + 14/35 = 24/35
Hope this helps.
If those are the possible answers i'm pretty sure you need to have a group of numbers you extract the mean from for example form the numbers 56, 77, 65, 87, and 99 the mean of the numbers would be 77 so once i have those we can figure it out
