4 years ago, the average age of a family of 4 members was 18 years. On the
addition of a child, the present average age is still the same. what is the present
age of the child ?
1) 5
2) 4
3) 2
4) 3
5) 6
Answers
Answer:
3) 2 is the answer
Step-by-step explanation:
Total age of the family 4 years ago = 4 x 18 = 72
At present,
Total age of the family excluding the child = 72 + 16 = 88
The average age of the family including child is given as 18
Total age of the family including child = 18 x 5 = 90
The age of the child = 90 - 88 = 2
Answer:
3) 2 years.
Step-by-step explanation:
Given that,
4 years ago a family of 4 members' average age was 18 years.
After addition of a new born child the average is still same i.e., 18 years.
Here, the total age of 4 family members will be :
→ 18*4
→ 72 years.
In addition of a new child the family members now is : (4 + 1) = 5 members.
As the average is still 18 years.
Therefore, the total age of 5 members :
→ 18*5
→ 90 years.
In the interval of 4 years the family's age is also increased by :
→ 4*4
→ 16 years.
Present age of the family will be :
→ 72 + 16 years.
→ 88 years.
We can say that,
➙ Age of the baby :
→ Present age of the family - Total age of the 5 members
→ 88 - 90
→ 2 years.
The age of the baby is 2 years.