# Consider the following data: Average marks in English Average marks in Hindi Girls 9 8 Boys 8 7 Overall average marks 8.8 x What is the value of x

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Consider the following data:

 Average marks in English Average marks in Hindi Girls 9 8 Boys 8 7 Overall average marks 8.8 x

What is the value of x in the above table?

1. 7.8
2. 7.6
3. 7.4
4. 7.2

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Correct Answer - Option 1 : 7.8

Formula used :

Average = Sum of all values/Number of values

Calculations :

Let the number of girls be 'g'

Let the number of boys be 'b'

Total number of boys and girls = b + g

Total marks of girls in English = 9 × g = 9g

Total marks of boys in English = 8 × b = 8b

Total marks in English 9g + 8b

According to the question

⇒ 8.8 = (9g + 8b)/(b + g)

⇒ b : g = 1 : 4

Number of boys = x and number of  girls = 4x

Total number of boys and girls = x + 4x = 5x

Now, total marks in Hindi

Marks of girls in Hindi = 8 × 4x = 32x

Marks of boys in Hindi = 7 × x = 7x

Average of marks in Hindi = (32x + 7x)/5x           (total marks = 32x + 7x)

⇒ 7.8

∴ The average marks in Hindi will be 7.8.