S = sum of the children's ages
Average of the 5 children's ages:
av = S / 5 = 8
S / 5 = 8
Multiply both sides by 5
S = 8 ∙ 5
S = 40
Sum of 5 children ages = 40
Let the father's age = f
The average, of 6 persons ( 5 children and the father):
( S + f ) / 6 = 8 + 7
( S + f ) / 6 = 15
( 40 + f ) / 6 = 15
Multiply both sides by 6
40 + f = 15 ∙ 6
40 + f = 90
Subtract 40 to both sides
40 + f - 40 = 90 - 40
f = 50
So the father is 50 years old
the average age of 5 children is 8 years. if the age of the father is included , the average increased by 7 years. find the age of the father.
2 answers
The average age of four childrens is 8 years which is incredible for year when the age of the father is included find the age of the father