jennsoekwanto
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(right answer using ALGEBRA will get lots of points and brainliest!)

There are 23 boys and 35 girls on the school’s track and field team. After q boys and (q+4) girls graduate at the end of this year, the probability of selecting a boy at random to represent the school for an event becomes 2/5. Find the value of q.

Answer :

xKelvin

Answer:

q=7

Step-by-step explanation:

So, right now, there are 23 boys and 35 girls.

After q boys and q+4 girls graduate, the probability of selecting a boy at random is 2/5. In other words, we can write the following equation:

(23-q)/(58-q-(q+4))=2/5

The numerator represents the number of boys after graduating.

The denominator represents the total numbers after boys and girls graduate. The 58 is the current total (23+35) and the -q and -(q+4) is the amount of students that will graduate. Now, find q:

(23-q)/(58-q-q-4)=2/5

(23-q)/(54-2q)=2/5

Cross multiply:

5(23-q)=2(54-2q)

115-5q=108-4q

-5q=-7-4q

-q=-7

q=7

We can check this: 23-7=16 and 35-11=24. 16/(24+16)=16/40=2/5

TheAnimeGirl

Answer:

7

Step-by-step explanation:

Total students = 23 + 35 = 58

Now, it becomes,

[tex]58 - (q + q + 4)[/tex]

[tex] = 58 - (2q + 4)[/tex]

When there is a (-) in front of an expression parentheses , change the sign at each term .

[tex] = 58 - 2q - 4[/tex]

Collect like terms

[tex] = 54 - 2q[/tex]

Again,

[tex] \frac{23 - q}{54 - 2q} = \frac{2}{5} [/tex]

Apply cross product property

[tex]5(23 - q) = 2(54 - 2q)[/tex]

[tex]115 - 5q = 108 - 4q[/tex]

Move variable to L.H.S and change its sign

[tex] - 5q + 4q + 115 = 108[/tex]

Move constant to R.H.S and change its sign

[tex] - 5q + 4q = 108 - 115[/tex]

Calculate the sum or difference

[tex] - q = - 7[/tex]

The difference sign (-) will be cancelled in both sides

[tex]q = 7[/tex]

Hope this helps...

Good luck on your assignment ..

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