Aptitude - Problems on Ages - Discussion
Discussion Forum : Problems on Ages - General Questions (Q.No. 13)
13.
A person's present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old is the mother at present?
Answer: Option
Explanation:
Let the mother's present age be x years.
| Then, the person's present age = |  |
2 | x |  |
years. |
| 5 |
 |
|
2 | x + 8 | |
= | 1 | (x + 8) |
| 5 | 2 |
2(2x + 40) = 5(x + 8)
x = 40.
Discussion:
59 comments Page 4 of 6.
Ajith said:
1 decade ago
Good yuga! simplified!
Subru said:
1 decade ago
x=mother's age
sons age=2/5*x
x=40(answer)
sons age=100
how this possible
sons age=2/5*x
x=40(answer)
sons age=100
how this possible
Mrs pallavi said:
1 decade ago
Let the person age x, mother age y.
x=2/5*y............condn(1)
(x+8)=1/2(y+8).....condn(2)
from 1
5x-2y=0.........(a)
from 2
2x-y=-8 ..........(b)
from a & b
we get x=16 & y=40
Answer is 40.
x=2/5*y............condn(1)
(x+8)=1/2(y+8).....condn(2)
from 1
5x-2y=0.........(a)
from 2
2x-y=-8 ..........(b)
from a & b
we get x=16 & y=40
Answer is 40.
Mithu Sen said:
1 decade ago
Hey Yuga.
Thanks your way of explaination was very simple.
Thanks your way of explaination was very simple.
Bhanu prasad said:
5 years ago
Present Let mother age :X.
Person's age :2/5x.
After 8 years.
Then it converted into the present.
So.
Mother age:x-8.
Person age:2/5 (x-8).
He/person will be one-half of the age of his mother.
2/5 (x-8) = 1/2 (x-8)--->(1).
By solving equation (1) you can directly get an answer.
Why because we already feature/aftet8 yers converts into the present.
So,
X=40.
Person's age :2/5x.
After 8 years.
Then it converted into the present.
So.
Mother age:x-8.
Person age:2/5 (x-8).
He/person will be one-half of the age of his mother.
2/5 (x-8) = 1/2 (x-8)--->(1).
By solving equation (1) you can directly get an answer.
Why because we already feature/aftet8 yers converts into the present.
So,
X=40.
Bharathi.m said:
1 decade ago
Thanks yuga.
Aditya said:
1 decade ago
Hey can any one explain properly?
Jaz said:
1 decade ago
One-half meaning is 1/2 only.
Sam said:
1 decade ago
As far as I can see in the third step they have taken the LCM on Left hand side but didn't do that on the right hand side. Just wondering if I am right. And if that's the case why didn't they do the same on RHS (right hand side) ?
Shravya said:
1 decade ago
@Yuga how you simplified it can you please explain it. Your method is good but please can you tell how you calculated it.
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