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Ajit has a certain average for 9 innings. In the tenth innings, he scores 100 runs thereby increasing his average by 8 runs. His new average is:

A. 20

B. 21

C. 28

D. 32

Answer: Option C

Solution(By Examveda Team)

Let Ajit's average be x for 9 innings. So, Ajit scored 9x run in 9 innings.
In the 10th inning, he scored 100 runs then average became (x+8). And he scored (x + 8) × 10 runs in 10 innings.
Now,
$$\eqalign{ & \Rightarrow 9x + 100 = 10 \times \left( {x + 8} \right) \cr & {\text{or}},\,9x + 100 = 10x + 80 \cr & {\text{or}},\,x = 100 - 80 \cr & {\text{or}},\,x = 20 \cr & {\text{New}}\,{\text{average}} = \left( {x + 8} \right) \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 28\,{\text{runs}} \cr} $$

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Comments ( 40 )

  1. Sahil Choudhary
    Sahil Choudhary :
    2 months ago

    9x8 =72
    100-72 = 28 ans new avg

  2. Arjun Yadav
    Arjun Yadav :
    4 months ago

    Alright

  3. AMANI KAJIGIRI
    AMANI KAJIGIRI :
    6 months ago

    Alright

  4. Alif Santa
    Alif Santa :
    12 months ago

    Thanks

  5. Aanchal Singhal
    Aanchal Singhal :
    12 months ago

    Nice explaination

  6. Ziarul Islam
    Ziarul Islam :
    1 year ago

    Right

  7. Ranjit Nayak
    Ranjit Nayak :
    1 year ago

    Is it right

  8. Bhavya A
    Bhavya A :
    1 year ago

    How it becomes (x+8)

  9. VACUUM ENERGY
    VACUUM ENERGY :
    2 years ago

    Very helpful

  10. Anonymous
    Anonymous :
    2 years ago

    Average= Total or Sum / Number (Total divided by Number)

    For 9th inning
    x = T/9
    9x=T

    For 10th inning
    x+8=T/10
    10(x+8)=T

    9x+100=10(x+8)
    9x+100=10x+80
    x=20

    New Average:x+8=28

    _____________________________________

    Shortcut:

    Innings×increasing runs=Answer
    Then, Runs-Answer=New Average

    9×8=72
    Then, 100-72=28
    New Average:28

  11. Pratap Kumar
    Pratap Kumar :
    2 years ago

    10x8 = 80
    100-80 =20
    New increment = 20+8

  12. Pratap Kumar
    Pratap Kumar :
    2 years ago

    Let's do it in shortcut
    Assume Till 9th inng his avg will be x
    In 10th inng his score was 100 and his total avg increase by x+8
    I.e for previous 9 innengs 8 will be given to each inngs
    So 9*8 = 72 and for 10th inng it's already 100 so
    100-72=28

  13. Deva G
    Deva G :
    2 years ago

    Nice

  14. Tajul Islam
    Tajul Islam :
    2 years ago

    Thanks

  15. Renuka Kattulas
    Renuka Kattulas :
    2 years ago

    Awesome app mainly board writing idea 🙂👍

  16. Balaji Ontipuli
    Balaji Ontipuli :
    2 years ago

    Nice sir

  17. Rahman Ashik
    Rahman Ashik :
    2 years ago

    (9*8)= 72
    100-72=28

  18. Kundan Kumar
    Kundan Kumar :
    2 years ago

    I feel very good. Visit on this app.

  19. Durga Sankar
    Durga Sankar :
    2 years ago

    Salimreza Jim :
    100-(8*9)=28
    Nice Sir

  20. Amit Patil
    Amit Patil :
    2 years ago

    how can this possible?

  21. Wahid Zahoor
    Wahid Zahoor :
    2 years ago

    Well awsm app for good method has been

  22. Sujith Kumar
    Sujith Kumar :
    2 years ago

    Ok, Good.., But when student doing competitive exams we they short cut method, plz explain in short cut methods

  23. Irfan Khan
    Irfan Khan :
    2 years ago

    It's the so best learning website to improve mathematical calculation

  24. Salimreza Jim
    Salimreza Jim :
    2 years ago

    100-(8*9)=28

  25. Fardhus Sharker
    Fardhus Sharker :
    3 years ago

    Good

  26. Ashraful Islam
    Ashraful Islam :
    4 years ago

    Let, initial average = x
    Acq,
    10(x+8)-9x = 100
    x = 100-80 = 20
    New average = 20+8 = 28

  27. Ilaks ..
    Ilaks .. :
    4 years ago

    thanks

  28. Anju Napit
    Anju Napit :
    4 years ago

    thanks

  29. Lakshmi Kancharana
    Lakshmi Kancharana :
    4 years ago

    Good and clear explanation

  30. Sudhakar Prajapati
    Sudhakar Prajapati :
    4 years ago

    Good Solutions

  31. D Luffy
    D Luffy :
    5 years ago

    Didn't get it.

  32. Sarthak Jain
    Sarthak Jain :
    5 years ago

    Let Ajit's average be x for 9 innings. So, Ajit scored 9x run in 9 innings.
    In the 10th inning, he scored 100 runs then average became (x+8). And he scored (x+8)*10 runs in 10 innings.
    (9x+100)/10 = x+8 (since in 10th inning, 100 more then 9th inning and average gets increses by 8)
    therefore on solving this equation we get ,
    x=20
    But the new average is increased by 8 runs
    therefore x+8 i.e 20+8 = 28..

  33. Shivani Burman
    Shivani Burman :
    5 years ago

    Nice solution

  34. Bhartika Singh
    Bhartika Singh :
    5 years ago

    Can't understand

  35. Akbar Hajj
    Akbar Hajj :
    6 years ago

    c

  36. Ravi Kumar
    Ravi Kumar :
    6 years ago

    28

  37. Gopal Nayak
    Gopal Nayak :
    6 years ago

    Best questions

  38. Saltaf
    Saltaf :
    7 years ago

    c

  39. Anonymous
    Anonymous :
    7 years ago

    Its 28

  40. Sanjeevinaidu
    Sanjeevinaidu :
    7 years ago

    28

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