12,16,20,.....480 is an A.P.
find the sum
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Answer:
AP= 12,16,20...480
a=12
d=16-12=4
To find n and Sn
An= a+(n-1)d
480=12+(n-1)4
468=n-1(4)
117=n-1
118=n
Therefore there are 118 terms.
Sn= n/2 (2a+(n-1)d)
Sn= 118/2 (2(12)+(117)4)
Sn= 59(24+468)
Sn= 59(492)
Sn= 29028
Step-by-step explanation:
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