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?
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.
Nandhini said:
8 years ago
How to add 4? please explain the step in detail.
Pallavi said:
8 years ago
Here consider There current ages x and y.
So according to 1 st condition.
X-6/y-6=6/5 --------> (1)
And according to 2 and Condition
X+4/y+4=11/10 --------> (2)
Solving (1) and (2) we get
10x-11y=4 --------> cross multiplication of (1)
5x-6y=-6 --------> cross multiplication of (2)
10x-11y=4 --------> (3)
So multiplying -2 (5x-6y=-6) we get;
-10x+12y=12 --------> (4).
Solving equations (3) and (4) we get;
y =16.
That is Sagar age.
So according to 1 st condition.
X-6/y-6=6/5 --------> (1)
And according to 2 and Condition
X+4/y+4=11/10 --------> (2)
Solving (1) and (2) we get
10x-11y=4 --------> cross multiplication of (1)
5x-6y=-6 --------> cross multiplication of (2)
10x-11y=4 --------> (3)
So multiplying -2 (5x-6y=-6) we get;
-10x+12y=12 --------> (4).
Solving equations (3) and (4) we get;
y =16.
That is Sagar age.
Anushree said:
8 years ago
6 years ago means we have to subtract as per the formula. Then why did they add in this problem?
Atiqur said:
7 years ago
Thanks @Faruk.
Iba Krish said:
7 years ago
Well said @Neha.
Dhiraj wagh said:
7 years ago
How come 4, here?
Student said:
7 years ago
Well said @Pradnyaa.
BKPATEL said:
7 years ago
Good explanation @Pallavi.
KSRAJA said:
6 years ago
Here, first, understand the question.
6year ago, the ratio of the ages of Kunal and Sagar was 6 : 5. --> it means that ration of both is given for 6years ago.
So that, the present age is 6x+6 and 5x+6.
6year ago, the ratio of the ages of Kunal and Sagar was 6 : 5. --> it means that ration of both is given for 6years ago.
So that, the present age is 6x+6 and 5x+6.
Mayur baviskar said:
6 years ago
Let, Kunal present age = x.
& Sagar present age = y.
STEP1
6yr ago
(x-6)/(y-6)=6/5
5x-6y=-6 .----> eq(1)
STEP2:
4yr hence;
(x+4)/(y+4)=11/10.
10x-11y=4 ---->eq(2).
Solving eq. Simultaneously.
x=18 & y = 16.
Hence Sagar age is 16yr old.
& Sagar present age = y.
STEP1
6yr ago
(x-6)/(y-6)=6/5
5x-6y=-6 .----> eq(1)
STEP2:
4yr hence;
(x+4)/(y+4)=11/10.
10x-11y=4 ---->eq(2).
Solving eq. Simultaneously.
x=18 & y = 16.
Hence Sagar age is 16yr old.
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