# 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 10

^{th}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 )

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9x8 =72

100-72 = 28 ans new avg

Alright

Alright

Thanks

Nice explaination

Right

Is it right

How it becomes (x+8)

Very helpful

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

10x8 = 80

100-80 =20

New increment = 20+8

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

Nice

Thanks

Awesome app mainly board writing idea 🙂👍

Nice sir

(9*8)= 72

100-72=28

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Salimreza Jim :

100-(8*9)=28

Nice Sir

how can this possible?

Well awsm app for good method has been

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

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

100-(8*9)=28

Good

Let, initial average = x

Acq,

10(x+8)-9x = 100

x = 100-80 = 20

New average = 20+8 = 28

thanks

thanks

Good and clear explanation

Good Solutions

Didn't get it.

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..

Nice solution

Can't understand

c

28

Best questions

c

Its 28

28