?
The average of a group of men is increased by 5 years when a person aged of 18 years is replaced by a new person of aged 38 years. How many men are there in the group?
Answer & Solution
Correct Answer:
Option
B
Let N be the no. of persons in the group.
Required number of person is given by;
Member in group × aged increased = difference of replacement
N × 5 = 38 - 18
Or, 5N = 20
Or, N = 4
Required number of person is given by;
Member in group × aged increased = difference of replacement
N × 5 = 38 - 18
Or, 5N = 20
Or, N = 4
Join the Discussion
Login to post a comment or share your explanation.
LoginNy=x,again x+20/n=y+5
X+20=ny+5n
X+20=x+5n
X=4
Let no. of persons=n
sum of all persons age=s
A person of age 18 is replaced by person with age 38
So, as per question
(s+38-18)/n=(s/n) + 5
s+20=s+5n
n=20/5=4
A/Q,
X(y+5)-xy=38-18
Xy+5x-xy=20
5x=20
X=4
Difference in age=38-18=20
So increase of 5 years will be distributed among 20/5= 4 persons
Kindly elaborate it