Question
There are 4 children in a family. The average age of the
children is 9 years. If the present age of their mother and father is added, the average age of the whole family becomes 15 years. If the age of the father is 4 years more than that of the mother, find the present age of the mother.Solution
ATQ, Let the present age of the mother be x years. So, the present age of the father = x+4 years. Sum of the present age of the four children = 9×4=36 years. Sum of the present age of the whole family = 36+x+(x+4)=15×6. 2x+4=90−36 2x=50 x=25 Therefore, the present age of the mother = 25 years.
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