three arithmetic progressions with sum of first 5 terms as 30
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Answered by
2
Answer:
Step-by-step explanation
Sn = 30 where n = 5
For an AP with a = first term
d = common difference
Sn =
Substituting in above equation…
∴ 2a + (5-1) × d = 12
∴ 2a + 4d = 12
∴ a + 2d = 6
i) Let a = 2, hence d = 2
Sequence is 2,4,6,8,10…
ii) Let a = 4, hence d = 1
Sequence is 4,5,6,7,8…
iii) Let a = 6, hence d = 0
Sequence is 6,6,6,6,6…
Hence, 3 sequences are found.
Answered by
2
Answer:
The three arithmetic progressions are
i)0,3,6,....
ii)2,4,6,....
iii)4,5,6,....
Step-by-step explanation:
n=5
S5=30
S5=(5/2)(2a+4d)
30=5(a+2d)
a+2d=6
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