Respuesta :

Answer:

4.  300 girls

5.  38 fish

6.  36 points

7.  115 marbles

8.  18 gray colored cars

Step-by-step explanation:

4.

 30 = 500

18G       x

30x = 500 (18)

x = 300 girls

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5.

2.5 mils  =   8 miles  

12 fish              x

2.5x = 8 (12)

x = 96/2.5

x = 38 fish

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6.

 8 mins   =   21 mins

14 points            x

8x = 21 (14)

x = 294/8

x = 36 points

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7.

32 marbles   =             x        

 5 inches             18 inches

5x = 32 (18)

x = 576 / 5

x = 115 marbles

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8.

140 cars =   15 cars  

    x              2 gray

15x = 140 (2)

x = 280 / 15

x = 18 gray colored cars

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Answer:

  1. 3000 girls
  2. 38 fishes
  3. 37 points
  4. 115 marbles
  5. 19 gray coloured cars

Step-by-step explanation:

Let the unknown values be x

1.

30 class mates = 1 class room

18 girls in 1 classroom

18 girls in 30 classmates

x girls in 5000 class mates

[tex]18\:girls= 30\:students\\x\:girls = 5000\:students\\\\Cross\:Multiply\\\\30x = 90000\\\\Divide\:both\:sides\:by\:30\\\frac{30x}{30} = \frac{90000}{30}\\ \\x = 3000\\= 3000 girls[/tex]

2.

[tex]2.5\:miles = 12 \:fishes\\8\:miles = x\:fishes\\\\Cross\:Multiply\\2.5x = 96\\\\Divide\:both\:sides\:of\:the\:equation\:by\:2.5\\\\\frac{2.5x}{2.5}=\frac{96}{2.5}\\ \\x = 38.4\\Approximately \: =38\:fishes[/tex]

3.

[tex]8\:minutes = 14\: points\\21 \:minutes = x \:points\\\\Cross\:Multiply\\8x = 294\\\\\mathrm{Divide\:both\:sides\:by\:}8\\\frac{8x}{8}=\frac{294}{8}\\\\Simplify\\x=\frac{147}{4}\\\\x = 36.75\\\\Approximately\:= 37\:points[/tex]

4.

[tex]32\:marbles = 5\:inches\\x\:marbles = 18\:inches\\\\Cross\:Multiply\\5x = 576\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\frac{5x}{5}=\frac{576}{5}\\\\x=\frac{576}{5}\\\\x =115.2\\= 115=\:marbles[/tex]

5.

[tex]2 \: gray\:colour= 15\:cars\\x\:gray= 140\:cars\\\\Cross\:Multiply\\\\15x = 280\\\\\mathrm{Divide\:both\:sides\:by\:}15\\\frac{15x}{15}=\frac{280}{15}\\\\Simplify\\x=\frac{56}{3}\\\\x =18.666\\Approximately ;\\19[/tex]