Aptitude - Problems on Ages - Discussion
Discussion Forum : Problems on Ages - General Questions (Q.No. 8)
8.
The sum of the present ages of a father and his son is 60 years. Six years ago, father's age was five times the age of the son. After 6 years, son's age will be:
Answer: Option
Explanation:
Let the present ages of son and father be x and (60 -x) years respectively.
Then, (60 - x) - 6 = 5(x - 6)
54 - x = 5x - 30
6x = 84
x = 14.
Son's age after 6 years = (x+ 6) = 20 years..
Discussion:
71 comments Page 3 of 8.
Pandi said:
1 decade ago
Now son age x and father age is y
then
x+y=60---->1
six years before son=x-6, father=5(x-6)
so
y-6=5(x-6)
y-6=5x-30
5x-y=24--->2
solve 1 and
get x=14
x is present age
after six years x+6=20
then
x+y=60---->1
six years before son=x-6, father=5(x-6)
so
y-6=5(x-6)
y-6=5x-30
5x-y=24--->2
solve 1 and
get x=14
x is present age
after six years x+6=20
Rohan magar said:
1 decade ago
@Amit thanks yar. Your method is easy and simple to understand :).
Muhammad Umair Kabir said:
1 decade ago
Let 'F' be the Father's Age and 'S' be the Son's Age.
According to situation:
F+S = 60 EQ ---- 1
F-6 = 5(S-6) ,
Which is F-6 = 5S-30 EQ ---- 2
F = 5S -24 EQ ---- 3
Put this in EQ 1
5S - 24 + S = 60
6S = 84
S = 14
After 6 Years Sons age will be S = 14 + 6 = 20
According to situation:
F+S = 60 EQ ---- 1
F-6 = 5(S-6) ,
Which is F-6 = 5S-30 EQ ---- 2
F = 5S -24 EQ ---- 3
Put this in EQ 1
5S - 24 + S = 60
6S = 84
S = 14
After 6 Years Sons age will be S = 14 + 6 = 20
Nil_dhongde@yahoo.com said:
1 decade ago
s=x
f=y
x+y=60......................(1)
6 years ago
(y-6)=5(x-6)
i.e
y-6=5x-30
Therefore at present age we have
y-6+6=5x-30+6
i.e
y=5x-24
From (1)
x+5x-24=60
6x=84
x=14
Therefore after 6 yrs sons age will be
14+6=20
f=y
x+y=60......................(1)
6 years ago
(y-6)=5(x-6)
i.e
y-6=5x-30
Therefore at present age we have
y-6+6=5x-30+6
i.e
y=5x-24
From (1)
x+5x-24=60
6x=84
x=14
Therefore after 6 yrs sons age will be
14+6=20
Vijay Anand said:
1 decade ago
@Priya.
Your logic is correct but you have to subtract 12 from 60. You have subtracted 6 for sons age and for fathers age you have to subtract another 6 know so it will be 60-12 = 48 not 54.
If you want me to explain precisely means please let me know.
Your logic is correct but you have to subtract 12 from 60. You have subtracted 6 for sons age and for fathers age you have to subtract another 6 know so it will be 60-12 = 48 not 54.
If you want me to explain precisely means please let me know.
Sunil said:
1 decade ago
Fathers age 4 times of his son means.
Sons age X.
Fathers age 4x.
Or
Sons age 4x.
Fathers age x.
Which one is right ? How to solve explain ?
Sons age X.
Fathers age 4x.
Or
Sons age 4x.
Fathers age x.
Which one is right ? How to solve explain ?
Nandhini said:
1 decade ago
@Sunil.
Case I is right.
Logically father's age should be more than son's age.
So 4x is greater than x so its right to take son's age x and father's age 4x.
Case-II is logically wrong.
Let x=20 i.e father's age then
Son's age will be 80 i.e 4x.
How could a 20yrs father can have 80 yrs son.
Hence case - I is right sons age x and fathers age 4x.
Case I is right.
Logically father's age should be more than son's age.
So 4x is greater than x so its right to take son's age x and father's age 4x.
Case-II is logically wrong.
Let x=20 i.e father's age then
Son's age will be 80 i.e 4x.
How could a 20yrs father can have 80 yrs son.
Hence case - I is right sons age x and fathers age 4x.
Ashok said:
1 decade ago
Take father age = x.
Son age = y.
Sum of father+son = 60.
x+y = 60 eq(i).
6 yrs ago father age is 5 times the age of son.
x-6 = 5(y-6).
x-6 = 5y-30.
x = 5y-30+6.
x = 5y-24.
Sub x value in eq(i).
5y-24+y = 60.
6y = 60+24 = 84.
y = 14.
Then 6 yrs after the son age = 14+6 = 20 years.
Son age = y.
Sum of father+son = 60.
x+y = 60 eq(i).
6 yrs ago father age is 5 times the age of son.
x-6 = 5(y-6).
x-6 = 5y-30.
x = 5y-30+6.
x = 5y-24.
Sub x value in eq(i).
5y-24+y = 60.
6y = 60+24 = 84.
y = 14.
Then 6 yrs after the son age = 14+6 = 20 years.
Imran Ali Korai said:
1 decade ago
Present age of son = x.
Present age of father = 5x.
6 years ago.
Son's age = x + 6.
Father's age = 5x + 6.
Sum of their ages.
X+6+5x+6 = 60.
6x = 48.
X = 8.
Son's age = x+6 = 14.
After Six Year's
14+6 = 20.
Hence 20 is correct answer.
Present age of father = 5x.
6 years ago.
Son's age = x + 6.
Father's age = 5x + 6.
Sum of their ages.
X+6+5x+6 = 60.
6x = 48.
X = 8.
Son's age = x+6 = 14.
After Six Year's
14+6 = 20.
Hence 20 is correct answer.
Sudha said:
1 decade ago
We can solve like this also:
Father is mentioned as 'f'.
Son is mentioned as 's'.
Sum of father and son age ==> f+s = 60 ----- (1).
Before 6 years ==> (f-6) = 5(s-6).
F-5s = -24 -------------- (2).
Solve equation 1 and 2 we can get the value of s = 14.
The current age of son is ===> 14.
After 6 year ==> 14+6 = 20.
Father is mentioned as 'f'.
Son is mentioned as 's'.
Sum of father and son age ==> f+s = 60 ----- (1).
Before 6 years ==> (f-6) = 5(s-6).
F-5s = -24 -------------- (2).
Solve equation 1 and 2 we can get the value of s = 14.
The current age of son is ===> 14.
After 6 year ==> 14+6 = 20.
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