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Ratio Part - 3 (Age Problem)
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Age problem simplified

## Bharat Gupta is teaching live on Unacademy Plus

Bharat Gupta
Engineer by degree Mathematician by Heart. Having 22 years of teaching experience. More than 20000 students selected.

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sir navy ka exam to nhi diya tha lekin airforce m sara apka padaya hua aaya tha
a year ago
Bhai shi bta , mera aieforce ka 24ko h
Cd
Sir, in the last sum you just added 8 to the ratios 2*4 is to 18*4 which came out to be 16 is to 80. why can"t we do like this 1*4 is to 9*4 + 8 = 12 is to 44 . why is the answer not coming same in my process even if the ratio 16 years ago is same ( 2 is to 18 or 1 is to 9) ? please do clear my doubt. awaiting response from you
Vasav Sharma
15 days ago
As you can see 1:9 was converted to 2:18 by multiplying with 2. So now the difference is same and then only we can equate using units method. In case of 1:9 the difference was 0 and 6 . Refer to the question again.
Vasav Sharma
15 days ago
As you can see 1:9 was converted to 2:18 by multiplying with 2. So now the difference is same and then only we can equate using units method. In case of 1:9 the difference was 0 and 6 . Refer to the question again.
sir...Can't we take 8 : 24 for finding present age instead of 2:18 by decreasing the age by 8 years?
Ss
sir this trick doesn't work in every questions
Bharat Gupta
a year ago
It work with some condition
Ss
Saurabh shekhar
a year ago
what are those conditions sir help me plz..
Sir, In the notes section, all question are not present. Please also make sure that your notes will also complete if you provide.
Bharat Gupta
a year ago
I do not provide any notes
sir in the last ques why we did not consider the 1:9 ratio instead of 2:18 ratio ?
SAURABH ANAND
a year ago
So let me start from the beginning, initial ratios for both the conditions 16years ago and 8years hence is 1:9 and 1:3 respectively. We are moving from present to past that is 16years, to present and then adding 8years to the present. So net difference is 16+8= 24years. Now we represent this 24 years in ratio. For first ratio , 1:9 difference is 8 and for second ration 1:3 difference is 2. So we ,multiply 2 to the first ration hence 2:18 and 8 to the second ratio 8:24. Now we get common difference between both ratios that is 6. The 24years as calculated above is equivalent to 6units.
1. RATIO AND PROPORTION Class 3(Age)

2. Age Problem Increase and Decrease Two number are in the ratio 8:9. If 5 is added to each number, then their ratio becomes 9: 10. Find the greater number. . 54 b. 45 . 36 d. 40

3. Age Problem Increase and Decrease Two number are in the ratio 8: 9. If 5 is added to each number, then their ratio becomes 9: 10. Find the greater number. a. 54 b. 45 . 36 d. 40 2, 9 -H lo

4. Age Problem Age of two person are in the ratio 8 9. After 5 years their age ratio becomes 9 10. Find the present age of elder person. a. 54 b. 45 . 36 d. 40

5. Age Problem Age of two person are in the ratio 8: 9. After 5 years their age ratio becomes 9 10. Find the present age of elder person. a. 54 b. 45 . 36 d. 40 2, Ti lo

6. Ratio between two number is 4:5. If 4 is subtracted, then their ratio becomes 3:4. Find sum of these number. a. 30 b. 42 . 36 d. 27

7. Ratio between two number is 4:5. If 4 is subtracted, then their ratio becomes 3:4. Find sum of these number. a. 30 b. 42 . 36 d. 27 L+ 3 L4

8. Ratio between two number is 4:7. If 10 is added, then their ratio becomes 2:3. Find sum of these number. a. 45 b. 55 c. 66

9. Ratio between two number is 4:7. If 10 is added, then their ratio becomes 2:3. Find sum of these number. a. 45 b. 55 c. 66 4 3 !- 3

10. The ratio of present age of two boys is 5 6. After two years the ratio will be 7: 8. The ratio of their age after 12 years will be a. 11 12 b. 15 16 c. 17:18 d. 10 11