Question

A man was assigned to find the average
age of a class of 13 students. By mistake,
he included the 35 yr old teacher as well
and hence the average went up by 2 yr.
Find the actual average age of the class
ISBI Clerk (Mains) 20161
(a) 8.
(b) 7 y!
(c) 15 y
(d) 11 yr
) y
(e) 9 yr​

Answer 1

Answer:

7

Step-by-step explanation:

let the avg of 13 students is x.

he mentioned in question that by including teacher age avg incresed to 2years (i.e) new avg is x+2

• so 13(x)+35(1)/(14)=x+2
• 13x+35=(x+2)14
• 13x+35=14x+28
• x=35-28=7