# 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 ( 19 )

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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