Mrs. sharma is twice as old as her son twenty years ago she was 12 times the age of her son. find their present ages
Answers
Step-by-step explanation:
A man is twice as old as his son. 10 years ago, he was three times as old as his son. How old will his son be in 5 years time?
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Answer is 25 years.
Explaination :
Suppose Man is X year old.
Boy is Y year old.
Then, since man is twice as old as his son, means : X = 2 Y ( This is our equation #1 )
10 years ago man’s age = X - 10
10 years ago son’s age = Y - 10
Since 10 years ago man was 3 times as old as his son, means :
X - 10 = 3 ( Y - 10 )
=> X - 10 = 3Y - 30
=> X = 3Y - 30 + 10 { from step above, transferred left side to right side and so sign of ( -) changes to ( +)}
=> X = 3Y - 20 ( This is our equation #2 )
Now, with these 2 equations first we are trying to evaluate the value of Y, so minus equation #1 from equation #2 :
X = 3Y - 20
- X = 2Y
=> 0 = Y - 20
=> Y = 20
So current age of the son is 20 years, so in 5 years time his age would be 25 years.