Question

. A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family?

A. 28 4/7 B. 31 5/7 C. 32 1/7

Answer 1

Given :-

• A family consists of two grandparents, two parents and three grandchildren.
• The average age of the grandparents is 67 years.
• The average age of parents is 35 years.
• The average age of grandchildren is 6 years..

To Find :-

• What is the average age of the family ?

Formula used :-

• The average value in a set of numbers is the middle value, calculated by dividing the total of all the values by the number of values.

Solution :-

→ Total Grandparents = 2 .

→ Average of Them = 67.

So,

→ Total age of Both Grandparents = 67 * 2 = 134 Years. ------- Equation (1).

Similarly,

→ Total parents = 2 .

→ Average of Them = 35.

So,

→ Total age of Both parents = 35 * 2 = 70 Years. ------- Equation (2).

And,

Total grandchildren = 3 .

→ Average of Them = 6.

So,

→ Total age of 3 grandchildren = 6 * 3 = 18 Years. ------- Equation (3).

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Adding Equation (1) , (2) & (3) we get,

→ Total age of Family = 134 + 70 + 18 = 222 Years.

And,

→ Total Members in The family = 2 + 2 + 3 = 7 .

Hence,

→ Average Age of Family = ( Total Age) / (Total Members)

→ Required Average = (222/7) = 31(5/7) Years. (Option B).

Therefore, Average Age of Family is 31(5/7) Years.

Answer 2

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$\huge\tt{GIVEN:}$

• A family consists of two grandparents, two parents and three grandchildren.
• The average age of the grandparents is 67 years
• The average age of the parents is 35 years
• The average age of the grandchilden is 6 years.

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$\huge\tt{TO~FIND:}$

• The average of the family

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$\huge\tt{SOLUTION:}$

Now, we know that average = Sum of the total terms/Number of terms

Firstly, Let's find the total age of the family...

↪Total age of Grandparents = 67×2 = 134 years __(EQ.1)

↪Total age of Parents = 35 × 2 = 70 years ___(EQ.2)

↪Total age of grandchildren = 6×3 = 18 years ____(EQ.3)

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By adding all the equations,

↪Total age of the family = (134+70+18) years = 222 years

↪Total members in the family = 7

↪ Average of the whole family = (Total Age / Total Members)

↪ Average of the whole family = 222/7 or 31(5/7) years

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