Question

23.Two different batches of students of a coaching
class with average marks 80 and 90 respectively are
combined to form a third batch. The average marks of
the combined batch now changes to 84. What is the
ratio of the number of students in the first batch to
that in the second batch?
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Answer 1

Answer:

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Step-by-step explanation:

fhfeghjvvdccsthjyefdvhiytfchjrddwqfhjo

Answer 2

Answer:  3:2

Step-by-step explanation:

Let no. of students in 1st and 2nd batch be x and y

Average marks when batch combined will be :

$\frac{80x+ 90y}{x + y} = 84$

80x + 90y = 84x + 84y

90y - 84y = 84x - 80x

6y = 4x

6/4 = x/y

3/2 = x/y