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  1. The average of 6 consecutive natural numbers is K. If the next two natural numbers are also included, how much more than K will the average of these 8 numbers be?
    1. 1.3
    2. 1
    3. 2
    4. 1.8
Correct Option: B

Let 6 consecutive natural numbers are y , y + 1 , y + 2 , y + 3 , y + 4 , y + 5
The average of 6 consecutive natural numbers = K
Sum of 6 consecutive natural numbers = y + ( y + 1 ) + ( y + 2 ) + ( y + 3 ) + ( y + 4 ) + ( y + 5 )
y + y + 1 + y + 2 + y + 3 + y + 4 + y + 5 = 6K
⇒ 6y + 15 = 6K

⇒ y +
15
= K
6

⇒ y +
5
= K..........(1)
2

Again,
y + (y + 1) + ........(y + 6) + (y + 7)
8

=
8y
+
28
= y +
7
..........(ii)
882

Now, y +
7
- y -
5
= 1
22



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