The average of x occurring 5 times and y occurring 7 times is 37. Also, the average of x occurring 7 times and y occurring 5 times is 35. The value of y is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 42
Here x occurs 5 times and y occurs 7 times and the average of these 12 items will be 37.
Average = (Sum of observations/ number of observation)
37 = (x + x + x + x + x + y + y + y + y + y + y + y)/12
5x + 7y = 37× 12............(1)
Now according to the question,
The average of x occurring 7 times and y occurring 5 times is 35
7x + 5y = 35 × 12..........(2)
By solving both equations we get,
2y = 84
y = 42