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Q.

The average score of a cricketer for ten matches is 38.9 runs. If the average for the first six matches is 42, then find the average for the last four matches.

 A.

33.25

 B.

33.5

 C.

34.25

 D.

35

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Solution:
Option(C) is correct

Total sum of last 4 matches

$= (10 \times 38.9) – (6 \times 42)$

$= 389 – 252 = 137$

Average

\(=\dfrac{137}{4}\)

\(=34.25\)

Edit: For an alternate solution, check comment by Chirag Goyal.


(7) Comment(s)


Ali Jan
 ()

If there are (p+q) elements in a set but the average of p elements is 'r' and the average of q elements is 's' then the average of all the elements of the set is given by $$\frac{pr+qs}{p+q}$$

so here, p=6, q=4, r=42, s= x(unknown ) , average of all elements = 38.9

by substituting values in above formula we get

$$\frac {42*6+x*4}{6+4}=38.9$$

$$x=34.22$$



Chirag Goyal
 ()

Alternate Solution

$\text{Avg. of Last four Innings}$ $= 38.9 - \left(\dfrac{42-38.9}{4}\right)\times6 = 34.25$



Avijit
 ()

wrong ans......Sad



Vivek Joshi
 ()

I experienced (also saw in comments later)

Please change the answer..

Thnx.



Sibaram Behera
 ()

hi,the correct ans ic 'C' but it indicate wrong ans means 'D'.............PLEASE CHANGE THE OPTIONS



Ridhima
 ()

the solution is correct but the option chosen is C not D.



Ridhima
 ()

hey , the answer is correct but you have picked the wrong option.