Question

Two years ago the mean age of 40 people was 11 years. Now a person left the group and mean age is changed to 12 years then the age of the person who left the group is

Answer 1

Answer:

52 years

Step-by-step explanation:

(i)

2 years ago, the mean age of 40 people was 11 years.

Mean = Sum/Total

(2 + 11) = Sum/40

13 = Sum/40

520 = Sum.

(ii)

Given that 1 person left(40 - 1 = 39) the group and mean changed to 12 years.

Mean of 39 people = Sum/Total

12 = Sum/39

Sum = 468.

Now,

Find the age of the one that left the group:

= 520 - 468

= 52.

∴ Therefore, the present mean age of the person who left is 52 years.

Hope it helps!