The average of 20 students is 12 years, if the teacher's age is included, average increases by one. The age of the teacher is:
A. 30 years
B. 33 years
C. 28 years
D. 35 years
Answer: Option B
Solution(By Examveda Team)
Average of 20 students = 12 yearsTotal age of 20 students
= 20 × 12
= 240 years
When teacher included average become 13 years
Now, total age 20 students and teacher
= 13 × 21 = 273 years
∴ Age of teacher
= 273 - 240
= 33 years
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Comments ( 1 )
Related Questions on Average
A. 125 km/hr
B. 75 km/hr
C. 135 km/hr
D. 120 km/hr
New average = 13 years
Among 20 students, the age distibuted from teacher's age = 20*1 = 20
Teacher age = 20+13 = 33