Question

6. The ratio of copper and zinc in an alloy is 9:5. If the weight of copper in the alloy i
s
48.6 grams, find the weight of zinc in the alloy.
. The ratio of boys and girls in a school is 8: 3. If the total number of girls be 375, find the
number of boys in the school.​

Answer 1

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QUESTION:

1) The ratio of copper and zinc in an alloy is 9:5. If the weight of copper in the alloy is 48.6 grams, find the weight of zinc in the alloy.

ANSWER:

☄️GIVEN:

• Ratio of copper and zinc in an alloy = 9:5
• Total weight of copper in alloy = 48.6gms

☄️TO FIND:

• Total weight of zinc in alloy = ?

☄️SOLUTION

Here,

weight of copper in the alloy = 48.6 g

The ratio of copper and zinc = 9:5

Then, Let, the weight of zinc = x

Now,

$\mathbb{ACCORDING \: TO \: QUESTION}$

=> 49:x = 9:5

$\sf = > \frac{48.6}{x} = \frac{9}{5}$

by, cross Multiplication

$\sf = > 5(48.6) =9x$

$\sf = > 243 =9x$

$\sf = > x = \frac{ \cancel{243}} { \cancel{9} } = 27g$

=> x = 27g

Hence, weight of zinc in the alloy = 27 g

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QUESTION:

The ratio of boys and girls in a school is 8: 3. If the total number of girls be 375, find the number of boys in the school.

ANSWER:

☄️GIVEN:

• Ratio of boys and girls in a school = 8:3
• Total no. of girls in a school = 375

☄️TO FIND:

• No. if boys in the school = ?

☄️SOLUTION:

Let, the no. of boys be 8x

and the no. of girls be 3x

Now,

$\mathbb{ACCORDING \: TO \: QUESTION}$

we are given that the no. if girls are 375

So, 3x = 375

$\sf \to x = \frac{375}{3}$

$\sf \to x = \frac{ \cancel{375}}{ \cancel{3}} = 125$

So, x = 125

Now, calculate the no. of boys

=> 8x

=> 8 × 125

=> 1000

Hence, the total no. if boys in the school = 1000

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Answer 2

Q.1)

The ratio of copper and zinc in an alloy is 9:5. If the weight of copper in the alloy is 48.6 grams , find the weight of zinc in the alloy.

Step-by-step explanation:

Given :-

• The ratio of copper and zinc in an alloy is 9:5.
• The weight of copper in the alloy is 48.6 grams.

To find :-

• Weight of zinc in the alloy.

Solution :-

Let the weight of zinc in the alloy be x grams.

• Weight of copper = 48.6 grams.

According to the question,

$\implies$48.6:x=9:5

$\implies$48.6/x = 9/5

$\implies$9x = 48.6×5

$\implies$9x=243

$\implies$x=243/9

$\implies$x=27

Therefore, the weight of zinc in the alloy is 27 grams.

___________________

Q.2)

The ratio of boys and girls in a school is 8: 3. If the total number of girls be 375, find the number of boys in the school.

Step-by-step explanation:

Given :-

• The ratio of boys and girls in a school is 8:3.
• Total number of girls is 375.

To find :-

• Number of boys in the school.

Solution :-

Let the number of boys in the school be x.

• Number of girls = 375

According to the question,

$\implies$x:375=8:3

$\implies$x/375=8/3

$\implies$3x=375×8

$\implies$3x=3000

$\implies$x=3000/3

$\implies$x=1000

Therefore, the number of boys is 1000.