12 + n = .5(42+n)
12 + n = 21 + .5 n
.5 n = 9
n = 18
A man is 42 years old and his son is 12 years old. In how many years will the age of the son be half the age of the man at that time? Explain!
2 answers
Other way to solve this question is:
Assume the years be x then
Son's age=12, Father's age=42.
After x years son's age will be half of father's age i.e. father's age will be twice of son's age
So
2(12+x)= (42+x)
24+2x = 42+x
2x-x = 42-24
x = 18
So after 18 years son's age will be half of father's age
To check:
12+18=30
and 42+18= 60
and hence son's age will be half the age of his father.
Assume the years be x then
Son's age=12, Father's age=42.
After x years son's age will be half of father's age i.e. father's age will be twice of son's age
So
2(12+x)= (42+x)
24+2x = 42+x
2x-x = 42-24
x = 18
So after 18 years son's age will be half of father's age
To check:
12+18=30
and 42+18= 60
and hence son's age will be half the age of his father.