5 year ago a man was 7 times as old as his son. After 5 years he will be thrice as old as his son . Find their present ages.
Answers
Answered by
3
hope it satisfy you
Attachments:
tasfin:
d.
Answered by
23
Heya !!!
Let the present age of man and his son be X and Y years.
Before 5 years age of man = ( X - 5 ) years.
Before 5 years age of his son = ( Y - 5) years.
According to question,
( X - 5) = 7 ( Y - 5)
X - 5 = 7Y - 35
X - 7Y = -35+5
X - 7Y = -30 ---------(1)
After 5 years age of man = ( X + 5) years.
After 5 years age of son = ( Y + 5) years.
According to question,
( X + 5) = 3 ( Y + 5)
X + 5 = 3Y + 15
X - 3Y = 15 - 5
X - 3Y = 10 ----------(2)
From equation (1) we get,
X - 7Y = -30
X = (-30 + 7Y ) ---------(3)
Putting the value of X in equation (2)
X - 3Y = 10
-30 + 7Y - 3Y = 10
4Y = 10 + 30
Y = 40/4 = 10
Putting the value of Y in equation (3)
X = -30 + 7Y = -30 + 7 × 10 = -30 + 70
X = 40 years.
Present age of man = X = 40 years
And,
Present age of son = Y = 10 years.
★ HOPE IT WILL HELP YOU ★
Let the present age of man and his son be X and Y years.
Before 5 years age of man = ( X - 5 ) years.
Before 5 years age of his son = ( Y - 5) years.
According to question,
( X - 5) = 7 ( Y - 5)
X - 5 = 7Y - 35
X - 7Y = -35+5
X - 7Y = -30 ---------(1)
After 5 years age of man = ( X + 5) years.
After 5 years age of son = ( Y + 5) years.
According to question,
( X + 5) = 3 ( Y + 5)
X + 5 = 3Y + 15
X - 3Y = 15 - 5
X - 3Y = 10 ----------(2)
From equation (1) we get,
X - 7Y = -30
X = (-30 + 7Y ) ---------(3)
Putting the value of X in equation (2)
X - 3Y = 10
-30 + 7Y - 3Y = 10
4Y = 10 + 30
Y = 40/4 = 10
Putting the value of Y in equation (3)
X = -30 + 7Y = -30 + 7 × 10 = -30 + 70
X = 40 years.
Present age of man = X = 40 years
And,
Present age of son = Y = 10 years.
★ HOPE IT WILL HELP YOU ★
Similar questions