The mean age of 15 pupils in a class is 14.2 years. One n...
The mean age of 15 pupils in a class is 14.2 years. One new pupil joined the class and the mean changed to 14.1 years. Calculate the age of the new pupil.
12.4 years
12.6 years
13.2 years
14.1 years
Correct answer is B
Mean=sum of agesno of pupils
Let the sum of the ages of the 15 pupils be x and the sum of the 16 pupils be y.
x15=14.2⟹x=14.2×15=213
y16=14.1⟹y=14.1×16=225.6
Age of new pupil=225.6−213=12.6
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