1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
iogann1982 [59]
3 years ago
15

There are 70 students in the school band. 40% of them are sixth graders, 20% are seventh graders, and the rest are eighth grader

s. How many band members are sixth graders? How many band members are seventh graders? What percentage of the band members are eighth graders?
Mathematics
1 answer:
dalvyx [7]3 years ago
5 0

Answer:

The band members of sixth graders are 28.

The band members of seventh graders are 14.

The percentage of the  band members eighth graders are 40% .

Step-by-step explanation

Formula

Percentage = \frac{Part\ value\times 100}{Total\ value}

As given

There are 70 students in the school band.

40% of them are sixth graders, 20% are seventh graders, and the rest are eighth graders.

Now first find out the  band members are sixth graders .

Percentage = 40%

Total value = 70

Put in the formula

40 = \frac{Number\ of\ band\ members\ are\ sixth\ graders\times 100}{70}

Number\ of\ band\ members\ are\ sixth\ graders = \frac{40\times 70}{100}

Number\ of\ band\ members\ are\ sixth\ graders = \frac{2800}{100}

Number\ of\ band\ members\ are\ sixth\ graders = 28

Therefore the number of band members are from sixth graders are 28 .

Now first find out the  band members are seventh graders .

Percentage = 20%

Total value = 70

20 = \frac{Number\ of\ band\ members\ are\ seventh\ graders\times 100}{70}

Number\ of\ band\ members\ are\ seventh\ graders = \frac{20\times 70}{100}

Number\ of\ band\ members\ are\ seventh\ graders = \frac{1400}{100}

Number\ of\ band\ members\ are\ seventh\ graders = 14

Therefore the number of band members are from seventh graders are 14.

Now find out the percentage of the eighth graders of the band members.

Total number of band members = sixth graders members + seventh grade members + eighth graders members

As  sixth graders members =  28

seventh grade members = 14

Total number of band members = 70

Put in the above

70 = 28 + 14  + eighth graders members

70 - 42 = eighth graders members

28 = eighth graders members

Put in the percentage formula

Percentage = \frac{28\times 100}{70}

Percentage = \frac{2800}{70}

Percentage = 40%

Therefore the percentage of the band members are eighth graders is 40 %.


You might be interested in
The LCM of 2 numbers is 60 and 1 of the numbers is 7 less than the other number. What are the numbers?
Phoenix [80]
Let's represent the two numbers by x and y.  Then xy=60.  The smaller number here is x=y-7.

Then (y-7)y=60, or y^2 - 7y - 60 = 0.  Use the quadratic formula to (1) determine whether y has real values and (2) to determine those values if they are real:

discriminant = b^2 - 4ac; here the discriminant is (-7)^2 - 4(1)(-60) = 191.  Because the discriminant is positive, this equation has two real, unequal roots, which are
        -(-7) + sqrt(191)
y = -------------------------
             -2(1)

and 

        -(-7) - sqrt(191)
y = ------------------------- = 3.41 (approximately)
             -2(1)

Unfortunately, this doesn't make sense, since the LCM of two numbers is generally an integer.


Try thinking this way:  If the LCM is 60, then xy = 60.  What would happen if x=5 and y=12?  Is xy = 60?  Yes.  Is 5 seven less than 12?  Yes.






5 0
3 years ago
Paul and Charlene are 420 miles apart. They start toward each other with Paul driving 16 mph faster than Charlene. They meet in
Thepotemich [5.8K]

Answer:

34 mph.    

Step-by-step explanation:

Let x be speed of Charlene, then speed of Paul will be x+16 as we are given that Paul is driving 16 mph faster than Charlene.

Let y be distance covered by Charlene, then distance covered by Paul will be 420-y.  

Now we will use formula \text{Speed}=\frac{\text{Distance}}{\text{Time}}. Upon using our given information we will get two equation and two unknowns as:  

x+16=\frac{420-y}{5}...(1)

x=\frac{y}{5}...(2)

Upon substituting x=\frac{y}{5} in 1st equation we will get,

\frac{y}{5}+16=\frac{420-y}{5}

Upon multiplying both sides of our equation by 5 we will get,

5(\frac{y}{5}+16)=420-y

5\times\frac{y}{5}+5\times 16=420-y    

y+80=420-y

y+80+y=420-y+y

2y+80=420

2y=420-80

2y=340

y=\frac{340}{2}  

y=170      

Upon substituting y=170 in 2nd equation we will get,

x=\frac{170}{5}

x=34

Therefore, Charlene's speed is 34 miles per hour.


6 0
3 years ago
Tom works in the cold food department in a supermarket. The thermometer shows the temperature of one of the freezers. The freeze
serg [7]
To return back to -18°C from -10°C, you would have to lower the temperature by -8°C to compensate for the difference.

Hope that helps!
5 0
3 years ago
Calculate the mean of: 4.6, 3, 8.1, 9, 12, 3, 9, 3.5, 7, 3.<br> 6.22<br> 5.8<br> 9<br> 3
harkovskaia [24]

Answer:

7.3

Step-by-step explanation:

The mean of 4.6, 3, 8.1, 9, 12, 3, 9, 3.5, 7, 3. 6, 22 , 5.8 , 9 , 3 is 7.3

3 0
3 years ago
Read 2 more answers
Suppose you are paid an annual salary, plus a bonus of 20% on annual sales over $500,000. Consider the two functions f(x) = x −
melisa1 [442]

Answer:

C. g\,\circ \, f (x) =g(f(x))

Step-by-step explanation:

Let be f(x) = x-500000 the excedent on annual sales and g(x) = 0.2\cdot x the bonus factor, to determine the bonus amount a composition of f(x) is g(x) must be done. That is:

g\,\circ \, f (x) =g(f(x))

Hence, the right answer is C.

7 0
3 years ago
Other questions:
  • At Daria's school 3/8 of students are left handed. If there are 320 students, how many of them are left handed
    8·1 answer
  • I need help on my mwr plz ohh help me
    14·1 answer
  • A bacteria culture is grown with a population of 45 million cells and kept under observation the cell population is found to dou
    11·1 answer
  • What is the value of k in the product of powers below?<br> 1<br> 0<br> -1<br> -3
    13·2 answers
  • Subtract and simplify (2y+14.6m+3.8)-(34.8m+15.6+2y)
    10·2 answers
  • Solve the inequality 7(x+2)-5&gt;3(x-1)
    12·1 answer
  • 5540 in scientific notation
    10·2 answers
  • What number is 30% of 100
    6·2 answers
  • #8: Linda is saving for retirement. She invest $12,000 in a retirement fund
    5·1 answer
  • (Geometry) Suppose the amount of water in the container is exactly enough to fill the cone. The container is held so that the he
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!