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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,
$$\eqalign{ & \Rightarrow 9x + 100 = 10 \times \left( {x + 8} \right) \cr & {\text{or}},\,9x + 100 = 10x + 80 \cr & {\text{or}},\,x = 100 - 80 \cr & {\text{or}},\,x = 20 \cr & {\text{New}}\,{\text{average}} = \left( {x + 8} \right) \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 28\,{\text{runs}} \cr} $$

This Question Belongs to Arithmetic Ability >> Average

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Comments ( 44 )

  1. Bimal Khadka
    Bimal Khadka :
    2 months ago

    Please explain in short cut method

  2. Syed Wasif
    Syed Wasif :
    3 months ago

    please explain in short cut methods.

  3. Abdulla Al
    Abdulla Al :
    4 months ago

    Thanks


  4. Deny Rigia
    Deny Rigia :
    10 months ago

    Where can I get the theory of this chapter

  5. Sahil Choudhary
    Sahil Choudhary :
    1 year ago

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

  6. Arjun Yadav
    Arjun Yadav :
    2 years ago

    Alright

  7. AMANI KAJIGIRI
    AMANI KAJIGIRI :
    2 years ago

    Alright

  8. Alif Santa
    Alif Santa :
    2 years ago

    Thanks

  9. Aanchal Singhal
    Aanchal Singhal :
    2 years ago

    Nice explaination

  10. Ziarul Islam
    Ziarul Islam :
    2 years ago

    Right

  11. Ranjit Nayak
    Ranjit Nayak :
    2 years ago

    Is it right

  12. Bhavya A
    Bhavya A :
    3 years ago

    How it becomes (x+8)

  13. VACUUM ENERGY
    VACUUM ENERGY :
    3 years ago

    Very helpful

  14. Anonymous
    Anonymous :
    3 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

  15. Pratap Kumar
    Pratap Kumar :
    3 years ago

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

  16. Pratap Kumar
    Pratap Kumar :
    3 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

  17. Deva G
    Deva G :
    3 years ago

    Nice

  18. Tajul Islam
    Tajul Islam :
    3 years ago

    Thanks

  19. Renuka Kattulas
    Renuka Kattulas :
    3 years ago

    Awesome app mainly board writing idea 🙂👍

  20. Balaji Ontipuli
    Balaji Ontipuli :
    3 years ago

    Nice sir

  21. Rahman Ashik
    Rahman Ashik :
    3 years ago

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

  22. Kundan Kumar
    Kundan Kumar :
    3 years ago

    I feel very good. Visit on this app.

  23. Durga Sankar
    Durga Sankar :
    3 years ago

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

  24. Amit Patil
    Amit Patil :
    3 years ago

    how can this possible?

  25. Wahid Zahoor
    Wahid Zahoor :
    3 years ago

    Well awsm app for good method has been

  26. Sujith Kumar
    Sujith Kumar :
    4 years ago

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

  27. Irfan Khan
    Irfan Khan :
    4 years ago

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

  28. Salimreza Jim
    Salimreza Jim :
    4 years ago

    100-(8*9)=28

  29. Fardhus Sharker
    Fardhus Sharker :
    4 years ago

    Good

  30. Ashraful Islam
    Ashraful Islam :
    5 years ago

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

  31. Ilaks ..
    Ilaks .. :
    5 years ago

    thanks

  32. Anju Napit
    Anju Napit :
    5 years ago

    thanks

  33. Lakshmi Kancharana
    Lakshmi Kancharana :
    6 years ago

    Good and clear explanation

  34. Sudhakar Prajapati
    Sudhakar Prajapati :
    6 years ago

    Good Solutions

  35. D Luffy
    D Luffy :
    6 years ago

    Didn't get it.

  36. Sarthak Jain
    Sarthak Jain :
    7 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..

  37. Shivani Burman
    Shivani Burman :
    7 years ago

    Nice solution

  38. Bhartika Singh
    Bhartika Singh :
    7 years ago

    Can't understand

  39. Akbar Hajj
    Akbar Hajj :
    7 years ago

    c

  40. Ravi Kumar
    Ravi Kumar :
    7 years ago

    28

  41. Gopal Nayak
    Gopal Nayak :
    7 years ago

    Best questions

  42. Saltaf
    Saltaf :
    8 years ago

    c

  43. Anonymous
    Anonymous :
    8 years ago

    Its 28

  44. Sanjeevinaidu
    Sanjeevinaidu :
    9 years ago

    28

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