The mean is found by dividing the sum of all terms by the number of terms present in the set.
Set up the equation:

The mean of this sequence is
5.
31=2y-5
Add 5 on both -5+5 which cancels out and 31+5 which is 36 and then divide 36 by 2 which equals to 18.
So y=18 hope this helped (':
Answer:
I don't know much about this but my teacher said it would be 16.48 or 164.8
Try making a picture that include adding blocks to make a wall or a kid playing with building blocks.
3 is the remainder because the closest is 7 times 21 so it’s remainder 3