This is an arithmetic series, where S5 means the sum of the first 5 numbers in the series. The general formula is:
Sn = (n/2)(a1 + an)
So,
a1 = 1 + 5/2(1) = 3.5
a5 = 1 + 5/2(5) = 1.5
S5 = (5/2)(3.5+1.5)
S5 = 12.5
<em>The answer should be 12.5</em>
<span>Hi, A cylinder has 3 faces - 2 circle ones and a rectangle</span>
Rewrite the fractions so they have a common denominator
3/4 = 15/20
Now add:
4 15/20 + 7 11/20 = 11 26/20
26/20 simplifies to 1 3/10
11 + 1 3/10 = 12 3/10 total minutes
76+20%= 91.2
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