Respuesta :
Answer:
1. B
2. A (n ≤ 13)
3. A (2m - 7)
4. B (8x+8y)
5. School C
6. C (6.08 pounds)
7. A (5 + 3p ≥ 30)
8. A (95 + 25x + 25y)
9. D (29)
10. A (Add 3 to both sides)
11. C (Malia)
12. C (n ≤ 48)
13. TRUE
Step-by-step explanation:
1.
We need to find 8.45% of each of them so that the answer is 2.1 hours.
For 20 hours: 8.45% of 20 = 0.0845 * 20 = 1.69 hours (this is not the answer)
For 25 hours: 8.45% of 25 = 0.0845 * 25 = 2.11 hours (this is the answer)
For 10 hours: 8.45% of 10 = 0.0845 * 10 = 0.85 hours (this isn't it)
For 18 hours: 8.45% of 18 = 0.0845 * 18 = 1.52 hours (this is not it)
We see that option B is right.
2.
Macy has $95.
She buys $12.99 worth of stationery. She now was 95 - 12.99 = $82.01
She needs to keep $42 intact for skateboard, so she can spend remaining on ice-cream bars.
She can spend [tex]82.01-42=40.01[/tex] for ice cream bars each worth 3.07.
Number of ice-cream bars, n, she can buy for 40.01 is [tex]\frac{40.01}{3.07}=13.03[/tex]. SHE CAN'T BUY 0.03 (the fractional amount) ice-cream bars, so the maximum is 13.
Answer choice A is right (n ≤ 13)
3.
We need to use the distributive property ([tex]a(b+c)=ab+ac[/tex]) to expand and them add like terms. The steps are shown below:
[tex]2(m-4)+1\\=2m-8+1\\=2m-7[/tex]
Answer choice A is right (2m - 7)
4.
Total number roses is = total red roses and total white roses
total red roses = x groups of 8 in each group = 8x
total white roses = y groups of 8 in each group = 8y
Hence, total = 8x + 8y
Answer choice B is right.
5.
We divide "number of students who like sandwiches" by "total number of students" , then multiply by 100 to get the percentage. Which ever is the greatest, is the answer. Let's do for each:
School A: [tex]\frac{12}{38}*100=31.58[/tex]%
School B: [tex]\frac{9}{48}*100=18.75[/tex]%
School C: [tex]\frac{10}{26}*100=38.46[/tex]%
School D: [tex]\frac{8}{24}*100=33.33[/tex]%
School C has the greatest percentage.
6.
Subtracting 25.2 from 86 will give us the amount of flour Sam used in last 10 days.
Amount used = 86 - 25.2 = 60.8 pounds
Since he used same amount for each day, we can divide 60.8 by 10 to get how much he used each day.
So, [tex]\frac{60.8}{10}=6.08[/tex] pounds used each day
Answer is C, 6.08 pounds
7.
"Score" needs to be atleast 30. Let first round score be 5 (given) and each of the three remaining rounds's score be p. So,
Score = 5 + 3p
This SCORE NEEDS to be ATLEAST 30, which means "5 + 3p should be greater than or equal to 30"
First answer choice is right (5 + 3p ≥ 30)
8.
First day printed = 95 (given)
Second day printed = 25 barcodes per minute for x minutes = 25x AND 25 barcodes per minute for y minutes = 25y
Subtotal is 25x+25y
Total in 2 days = 95 + 25x + 25y
Answer choice A is right.
9.
Let first number be x, so next consecutive number is x + 1 and the next one is x + 2. We take the sum and equate to 84 and solve:
[tex]x+(x+1)+(x+2)=84\\3x+3=84\\3x=84-3\\3x=81\\x=\frac{81}{3}=27[/tex]
Hence, the 3 numbers are 27, 28, and 29. The largest is 29, answer choice D is right.
10.
The question is
[tex]\frac{3}{4x}-3=-18[/tex]
The first step would be to "isolate" the terms with x's and constant terms. So we sould take 3 to the right hand side.
Adding 3 to both sides "eliminates" 3 from left and takes it to the right.
Answer choice A is right (Add 3 to both sides)
11.
Finding the respective PERCENTAGES will give us the answers. The greatest amount is what we are looking for. Let's find it.
Zak = 15% of 56 = 0.15 * 56 = 8.4 pages
Karen = 12% of 64 = 0.12 * 64 = 7.68 pages
Malia = 14% of 68 = 0.14 * 68 = 9.52 pages
Ali = 10% of 72 = 0.10 * 72 = 7.2 pages
We see that Malia reads the most. Answer choice C is right (Malia)
12.
Subtracting John's weight (100) from maximum the elevator can carry (340) will give us the amount alloted for the packages.
Amount alloted for packages = 340 - 100 = 240
Since each package weights 5, the MAXIMUM is [tex]\frac{240}{5}=48[/tex]
It means "the number of packages, n, can be LESS THAN or EQUAL to 48"
Answer choice C is right (n ≤ 48)
13.
We can simplify the expression by using distributive property ([tex]a(b+c)=ab+ac[/tex]) and collecting like terms to fully simplify the expression. let's do it:
[tex]3x-4(2x-5)\\=3x-8x+20\\=-5x+20[/tex]
Indeed the expression is equal to "20 - 5x" (the two terms are just placed differently)
Answer is TRUE
