Aptitude - Problems on Ages - Discussion

Discussion Forum : Problems on Ages - General Questions (Q.No. 7)
7.
Six years ago, the ratio of the ages of Kunal and Sagar was 6 : 5. Four years hence, the ratio of their ages will be 11 : 10. What is Sagar's age at present?
16 years
18 years
20 years
Cannot be determined
None of these
Answer: Option
Explanation:

Let the ages of Kunal and Sagar 6 years ago be 6x and 5x years respectively.

Then, (6x + 6) + 4 = 11
(5x + 6) + 4 10

10(6x + 10) = 11(5x + 10)

5x = 10

x = 2.

Sagar's present age = (5x + 6) = 16 years.

Discussion:
128 comments Page 12 of 13.

Mit Patel said:   5 years ago
Present ages of Kunal is x and sagar is y.
Six years ago,

X-6/y-6=6/5.

After solving this equation I get,
5x-6y=-6.

And 4 year hence,
X-2/y-2=11/10.
After solving this equation I get,
10x-11y=-2.

Now solving this two-equation.

Sagar age is 10 year at present.
(1)

Pallavi said:   5 years ago
@All.

By using the Ratio method:

K S (yrs)
6 : 5 ( -6).. 6 yrs ago so minus.
11 : 10 (+4)... After 4 yrs so add 4.
5 ratio = 10... The vertical difference between both the ratio is 5 i.e equal to the sum of the year (add yrs even if signs are different).

So, 1ratio = 2.
Then 2 * 5= 10 ... Sagar ratio is 5.
10+6= 16 yrs --- Add 6 for present age.

Rohini said:   5 years ago
Thank you @Faruk.

Sreekanth said:   5 years ago
No @Faruk.

He takes six year ago as 6x.

If we take present age as x=5.
Then six years ago in 6x we assign x=5 and it becomes 30.

How it will be right?

Swanali lakahane said:   5 years ago
I don't know why 6 is added here, because here it is given ago.

So, please tell me, anyone.

Sangay Wangchuk said:   5 years ago
@Swanali.

6 is added because it clearly says that six years ago their age was 6:5. And we are asked to find present ages so we have to add 6 on their age.
(2)

Jashobanta Nayak said:   5 years ago
Here 'ago' is only mentioned for "hence", so 6 will be added.

Koknalthang said:   5 years ago
Sir.

Why 5x+6? Why not 5x+4 or 5x-4? Please, anyone, explain.
(7)

Gowtham G R said:   4 years ago
Can u explain how (6x+6)+4, It will be (6x+4) right?

Because 4 years hence means we have to add (6x)+4.
(4)

Yamu said:   4 years ago
Why we are adding 6x+6? I cannot understand this, Please explain me.
(7)


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