An auditorium has 30 rows of seats. The first row has 20 seats, the second row has 22 seats, the third row has 24 seats, and so
on. What is the total seating capacity of the auditorium
2 answers:
An = a1 + (n-1)*d
n = term to find = 30
a1 = first term = 20
d = common difference = 2
a30 = 20 + (30 - 1) * 2
a30 = 20 + 29 * 2
a30 = 20 + 58
a30 = 78
sn = (n (a1 + a30)) / 2
s30 = (30(20 + 78) / 2
s30 = (30(98) / 2
s30 = 2940/2
s30 = 1470 <===
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
Equals
1438
You might be interested in
Answer:
(0,0)
(2,2)
(0,1)
Step-by-step explanation:
All of these points lie inside
Answer:
10x-6
Step-by-step explanation:
Answer:
-3x+8
Step-by-step explanation:
-2x-x+8=
-3x+8
Answer:

Step-by-step explanation:
slope :
= 0.5