The average of 10 observations is 54 where 1st ,3rd and 7th observations are same. after removing these three observations the average becomes 60. find the value of 1st observations?
1. 65
2. 40
3. 50
4. 30
1. 65
2. 40
3. 50
4. 30
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Answer:
The value of 1st observation is 40
Step-by-step explanation:
Let us assume that the given three same observations is 3x and the sum of rest is y.
(3x+y)/10=54
3x+y=54*10
3x+y=540
If we remove the three observations
y/7=60
y=60*7
y=420
Therefore
3x+420=540
x=(540-420)/3
x=40
The first observation is 40
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