The average marks of four subjects is 120. If 33 was misread as 13 during the calculation, what will be the correct average?
A. 122
B. 120
C. 125
D. 121
Answer: Option C
Solution(By Examveda Team)
$$\eqalign{ & {\text{Correct average}} \cr & = 120 + \left( {\frac{{33 - 13}}{4}} \right) \cr & = 120 + 5 \cr & = 125 \cr} $$Solve while reading method:
Average given is 120.
Difference of 33 and 13 is 20.
That means 20 must be added to total.
Then average of is and so must be added to average, i.e.
Correct average = 120 + 5 = 125
Join The Discussion
Comments ( 6 )
Related Questions on Average
A. 125 km/hr
B. 75 km/hr
C. 135 km/hr
D. 120 km/hr
120- 20/4=115 is correct average
115
Total 120*4 = 480
480+33-13=500
Correct average = 500/4= 125 (Ans)
Sum of 4 subjects is 4×120=480
33 is misread as 13
The difference between 33-13=20
New sum of 4 subjects is 480+20=50p
Average of new 4 subjects is 500/4=125
average of misread = (33-13)/4 = 5
Correct average = 120 + 5 = 125
120*4=480 , 480-13+33=500 500/4=122.22
Shouldn't we solve it according to above mentioned method?