<span>Half-span is half of span. Pitch of the roof is calculated as rise/(span/2). In this case, rise is 8 feet and span is 30 feet. So, the pitch can be calculated as 8/(30/2) or 8/15. Pitch is normally represented as the number of inches of rise per foot. So, to reduce 8/15 to match a foot, we multiply it by 12. So, (8/15) * 12 gives us 6.4 inches of rise per foot.</span>
W=20.3
solve what's in the parenthesis, move the terms, calculate, then divide both sides.
Solution
The 1st term = -3
15th term = 53
15th term = a + d(n-1)
53 = -3 + d(15- 1) [Here n = 15)
53 + 3 = d(14)
14d = 56
d = 4
The common difference is 4.
