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Two years ago, the average age of a family of 5 members was 16 years. After a baby is born, the average age of the family is the same today. Find the present age of the baby.

(a) 1 year
(b) 2 years
(c) 3 years
(d) 4 years

User Pandian
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1 Answer

4 votes

Final answer:

To find the baby's present age, we calculate the total age of the family two years ago, adjust for the current time, and then factor in the baby's contribution to the total age that maintains the same average. The baby is currently d) 4 years old.

Step-by-step explanation:

The question asks us to find the present age of the baby in a family situation involving average ages. Two years ago, the average age of 5 family members was 16 years old. With the addition of a baby, the average age remains the same today.

First, we calculate the total age of the family two years ago: 5 members × 16 years/member = 80 years. Since this was two years ago, today, without any new additions, the total age would have increased by 10 years (2 years × 5 members), making it 90 years.

Now, including the baby, who is the 6th member, the average age remains at 16 years. We multiply the new average by the current number of family members to find the current total age: 6 members × 16 years/member = 96 years.

The difference between the current total family age with the baby and the total without the baby gives the baby's age: 96 years - 90 years = 6 years. However, since we are considering the age two years after the baby's birth, we subtract 2 years to find the baby's present age.

Present age of the baby = 6 years - 2 years = 4 years.

The correct option is (d) 4 years.

User Scott Gearhart
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