A conference hall has 30 rows. Each successive row contains one additional seat. If the first row has 15 seats, how many seats are in the hall? *
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A conference hall has 30 rows. Each successive row contains one additional seat. If the first row has 15 seats, how many seats are
Answer:
885
Step-by-step explanation:
D- 1
A1 - 15
N- 30
TO FIND AN;
AN=A1 +(N-1) D
an=15+(30-1)1
an=15+ (29)(1)
an=15+29
an=44
TO FIND THE SUM;
D-1
AN-44
A1- 15
N- 30
SN = N/2 (A1+AN)
S30= 30/2 (15+44)
S30= 15(59)
S30= 885