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 10 of 13.
Sarbajeet said:
9 years ago
All I understand but here the equation says 6 years ago and not after 6 years then how it can be x + 6. Can you explain why it could not be x - 6 when the question states the word 'ago'?
Wasiq pirzada said:
9 years ago
It's very easy First look at the first sentence there is mentioned "6 years ago" ok Fine but the main thing is present 6 years ago means (-6) and 4 years hence will be aftter 4 from present a total of 10 should be added instead of +6 and +4.
Wasiqpirzada said:
9 years ago
@All.
Remember when there is ago and hence always use + tool never subtract it.
Remember when there is ago and hence always use + tool never subtract it.
Mahesh said:
9 years ago
Good explanation @Faruk.
Karthik said:
9 years ago
I think (6x+10) means bringing the ages from past to present and then it was taken as present condition and +4 for the future age.
Neha Deogade said:
9 years ago
Thanks @Faruk.
Vasantha said:
9 years ago
@ Faruk.
Good explanation.
Good explanation.
Ana said:
9 years ago
Let us find the equation for 6 years ago.
x-6/y-6 = 6/5.
5(x-6)=6(y-6) ; 5x-30 = 6y-36 ; 5x-6y = -6-------- (1).
Let us find the equation for four years hence(later)
x+4/y+4 = 11/10.
10(x+4) = 11(y+4) ;10x+40 = 11y+44 ; 10x-11y= 4-------- (2)
Subtract eq (1)&(2).
10x-12y=-12 multiply by 2.
-10x+11y = -4.
----------------
Answer: y=16 Sagar present age.
x-6/y-6 = 6/5.
5(x-6)=6(y-6) ; 5x-30 = 6y-36 ; 5x-6y = -6-------- (1).
Let us find the equation for four years hence(later)
x+4/y+4 = 11/10.
10(x+4) = 11(y+4) ;10x+40 = 11y+44 ; 10x-11y= 4-------- (2)
Subtract eq (1)&(2).
10x-12y=-12 multiply by 2.
-10x+11y = -4.
----------------
Answer: y=16 Sagar present age.
Sana said:
9 years ago
I don't understand this problem. In this, we want to substract 6x-6?
Narendra said:
9 years ago
Six year's ago that means we will do "_" ,why they adding+6 instead of -6?
Anybody help me.
Anybody help me.
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