Question

how do you solve The seats at a local baseball stadium are arranged so that each row has five more seats than the row in front of it. If there are four seats in the first row, how many total seats are in the first 24 rows?

Answer 1

You have an arithmetic series
a1=4,
a2=4+5=9= a1+5
a3=9+5=14=a1+2(5)
.................
an=a1+(n-1)(5)
n=24
a_(24)=a1+23*5=4+23*5=119
Sn= n(a1+an)/ 2=
S_(24)= 24(4+119)/2=1476

Answer 2

okay, what does that mean

Answer 3

Guykubpommm helpppp me!!

Answer 4

a1 = 4 and a2 = 4 +5,a3 = 4 +2*5 and then an = 4+(n-1)*5
so the sum is sigma(4+(n-1)*5) when n runs from 1 to 24

Answer 5

sigma(4+(n-1)*5) = sigma (4n-1)

Answer 6

so it is sigma4n - sigma1 = 4*24*25/2 - 24

Answer 7

get it?

Answer 8

yeah!! is it 1176

Answer 9

??

Answer 10

yep

Answer 11

YESSSSS. Thankkk you! your ammazing haha

Answer 12

thanks lol

Answer 13

no worries! haha

Answer 14

but no I figured it wrong haha

Answer 15

it is sigma(5n-1) = 5*24*25/2 - 24 = 1476 lol

Answer 16

yeahh I know but I still got it right on my work cause I just guessed the closet answer to the answer we figured the first time lol sooo its okay