Question

40.
The mean marks (out of 100) of boys and girls in an examination are
70 and 73 respectively. If the mean marks of all the students is the
examination is 71. Find the ratio of the number of boys to the number
of girls.

Answer 1

Answer:

You can solve by taking x and y instead of a and b

I hope this helped you

Answer 2

Answer:

2:1

Step-by-step explanation:

here's your answer:

let the no. of boys in the exam be "x"

let the no. of girls in the exam be "y"

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as we know....

total sum of all values: (mean)*(no. of observations)

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thus,

sum of marks obtained by the boys - 70*x = 70x

sum of marks obtained by the girls - 73*y = 73y

total sum of marks obtained - 71 (x + y)

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∴ 71 (x + y) = 70x + 73y

⇒ 71x + 71y = 70x + 73y

⇒ 71x - 70x = 73y - 71y

⇒ x = 2y

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∴ the ratio of the boys to the girls is 2:1

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hope it helps....

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