arrow
arrow
arrow
Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7. If the product of their present ages is 616, find the ratio of their present age
Question

Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7. If the product of their present ages is 616, find the ratio of their present age.

A.

12 : 13

B.

11 : 14

C.

15 : 17

D.

17 : 15

Correct option is B

Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7.
Let their ages be measure in terms of x, then their present ages are 5x + 7 and 7x + 7 respectively.
If the product of their present ages is 616,
Then (5x+7) (7x+7) = 616
35x2^2​ + 35 x + 49x + 49 = 616
35x2^2 + 84x + 49-616 = 0 ​
35x2^2 +84x-567 = 0 ​
=>7(5x2^2 + 12x-81) = 0 ​
→5x2^2 + 12x81 = 0 ​
= 5x2^2 + (27 – 15)x – 81 = 0 ​
5x2^2+ 27x-15x - 81 = 0 ​
= x (5x + 27) – 3(5x + 27) = 0
= (5x + 27) (x – 3) = 0
=>x=-27/5 or, x = 3

putting the value of x in 5x + 7 and 7x + 7

                                    =22:28

                                      =11:14

ratio of their present age = 11:14

Free Tests

Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB NTPC Graduate Level PYP (Held on 5 Jun 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 General Awareness Section Test 1

languageIcon English
  • pdpQsnIcon40 Questions
  • pdpsheetsIcon30 Marks
  • timerIcon25 Mins
languageIcon English

Similar Questions

test-prime-package

Access ‘RRB JE’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
353k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow