Examveda

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

Join The Discussion

Comments (51)

  1. Md. Rasel
    Md. Rasel:
    1 week ago

    Thanks

  2. Pawan Rajput
    Pawan Rajput:
    1 week ago

    Please use hindi language

  3. BISWAJIT SAHOO
    BISWAJIT SAHOO:
    1 month ago

    Translate to odia

  4. Teimonlang Phawa
    Teimonlang Phawa:
    1 month ago

    How do you assume that 8x

  5. Kailash Kathayat
    Kailash Kathayat:
    3 months ago

    Yo 9x+100 kasari bho?

  6. Magan Deep
    Magan Deep:
    10 months ago

    Can i get shortcut method of it

  7. Sudhakar Prajapati
    Sudhakar Prajapati:
    1 year ago

    Correct Answer 28

  8. Bimal Khadka
    Bimal Khadka:
    2 years ago

    Please explain in short cut method

  9. Syed Wasif
    Syed Wasif:
    2 years ago

    please explain in short cut methods.

  10. Abdulla Al
    Abdulla Al:
    2 years ago

    Thanks


  11. Deny Rigia
    Deny Rigia:
    3 years ago

    Where can I get the theory of this chapter

  12. Sahil Choudhary
    Sahil Choudhary:
    3 years ago

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

  13. Arjun Yadav
    Arjun Yadav:
    4 years ago

    Alright

  14. AMANI KAJIGIRI
    AMANI KAJIGIRI:
    4 years ago

    Alright

  15. Alif Santa
    Alif Santa:
    4 years ago

    Thanks

  16. Aanchal Singhal
    Aanchal Singhal:
    4 years ago

    Nice explaination

  17. Ziarul Islam
    Ziarul Islam:
    4 years ago

    Right

  18. Ranjit Nayak
    Ranjit Nayak:
    4 years ago

    Is it right

  19. Bhavya A
    Bhavya A:
    5 years ago

    How it becomes (x+8)

  20. VACUUM ENERGY
    VACUUM ENERGY:
    5 years ago

    Very helpful

  21. Anonymous
    Anonymous :
    5 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

  22. Pratap Kumar
    Pratap Kumar:
    5 years ago

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

  23. Pratap Kumar
    Pratap Kumar:
    5 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

  24. Deva G
    Deva G:
    5 years ago

    Nice

  25. Tajul Islam
    Tajul Islam:
    5 years ago

    Thanks

  26. Renuka Kattulas
    Renuka Kattulas:
    5 years ago

    Awesome app mainly board writing idea 🙂👍

  27. Balaji Ontipuli
    Balaji Ontipuli:
    5 years ago

    Nice sir

  28. Rahman Ashik
    Rahman Ashik:
    5 years ago

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

  29. Kundan Kumar
    Kundan Kumar:
    5 years ago

    I feel very good. Visit on this app.

  30. Durga Sankar
    Durga Sankar:
    5 years ago

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

  31. Amit Patil
    Amit Patil:
    5 years ago

    how can this possible?

  32. Wahid Zahoor
    Wahid Zahoor:
    6 years ago

    Well awsm app for good method has been

  33. Sujith Kumar
    Sujith Kumar:
    6 years ago

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

  34. Irfan Khan
    Irfan Khan:
    6 years ago

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

  35. Salimreza Jim
    Salimreza Jim:
    6 years ago

    100-(8*9)=28

  36. Fardhus Sharker
    Fardhus Sharker:
    6 years ago

    Good

  37. Ashraful Islam
    Ashraful Islam:
    7 years ago

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

  38. Ilaks ..
    Ilaks ..:
    7 years ago

    thanks

  39. Anju Napit
    Anju Napit:
    7 years ago

    thanks

  40. Lakshmi Kancharana
    Lakshmi Kancharana:
    8 years ago

    Good and clear explanation

  41. Sudhakar Prajapati
    Sudhakar Prajapati:
    8 years ago

    Good Solutions

  42. D Luffy
    D Luffy:
    8 years ago

    Didn't get it.

  43. Sarthak Jain
    Sarthak Jain:
    9 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..

  44. Shivani Burman
    Shivani Burman:
    9 years ago

    Nice solution

  45. Bhartika Singh
    Bhartika Singh:
    9 years ago

    Can't understand

  46. Akbar Hajj
    Akbar Hajj:
    9 years ago

    c

  47. Ravi Kumar
    Ravi Kumar:
    9 years ago

    28

  48. Gopal Nayak
    Gopal Nayak:
    9 years ago

    Best questions

  49. Saltaf
    Saltaf :
    10 years ago

    c

  50. Anonymous
    Anonymous :
    11 years ago

    Its 28

  51. Sanjeevinaidu
    Sanjeevinaidu :
    11 years ago

    28

Related Questions on Average