Answer:
John got 94 marks
Step-by-step explanation:
average = total numbers/ no. of students
77= x/16--------------1
78=x+y/17------------2
From 1 : x= 77*16= 1232--------------3
From 2: x+y= 78*17= 1326---------4
subtracting 3 from 4
y= 1326-1232= 94
Answer:
diameter=22
circumference=22pi
Step-by-step explanation:
diameter=2*radius
so 2*11=22
circumference=2pi*r
=2*11*pi
=22pi
Given:
The mean age of 5 people in a room is 26 years.
A person enters the room. The mean age is now 33.
To find:
The age of the person who entered the room.
Solution:
Formula for mean:

The mean age of 5 people in a room is 26 years.



The mean age is now 33. It means, the mean age of 6 people is 33.



Now, the age of the person who entered the room is
Required age = Sum of ages of 6 people - Sum of ages of 5 people
= 
= 
Therefore, the age of the person who entered the room is 68 years.