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Three years ago the average age of a family of six members was 19 years. A boy have been born, the average age of the family is the same today. What is the age of the boy?
- A1 year
- B1.5 years
- C2 years
- D2.5 years
Correct answer: A
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0
CCommunity
3 years ago
Total age of 6 members $ \large = 19 \times 6 = 114$
Now total age of these 6 members would be $ \large = 114 + (3 \times 6) = 132$
As a baby is born, let its age is $x$
Now average of 7 members would be $\large (132 + x ) / 7 = 19$
$ \large x = (19 \times 7 ) - 132$
$ \large x = 1 $
Total age of 6 members $ \large = 19 \times 6 = 114$
Now total age of these 6 members would be $ \large = 114 + (3 \times 6) = 132$
As a baby is born, let its age is $x$
Now average of 7 members would be $\large (132 + x ) / 7 = 19$
$ \large x = (19 \times 7 ) - 132$
$ \large x = 1 $
0
CCommunity
1 year
6 * 22 = 132
7 * 19 = 133
6 * 22 = 132
7 * 19 = 133