1,3,5 is an arithmetic sequence a)find the sum of first 20 terms of the sequence
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0
Answer:
The sum of first n terms of arithmetic series formula is given by the formula,
Where n = number of terms =20
a= first term =1
d= common difference of A.P. =3−1=2
On substituting the given values in the formula, we get
[2×1+(20−1)2]
=5[2+38]
=5[40]
=200
So, the sum of first 20 terms of the A.P. is 200
Step-by-step explanation:
Answered by
0
Answer:
Sum of 20 terms = 400
Step-by-step explanation:
a = 1
d = 2
n = 2
Sn = n/2 [2a + (n - 1) d]
S20 = 20/2 [2×1 + (20-1)2]
= 10 [2 + 19×2]
= 10 [2 + 38]
= 10 (40)
= 400
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