In an arithmetic progression the sum of first 11 terms is 14 and the sum of next 11 terms is 55 find the first term and common difference.
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Answer:
first term = 39/11 , common difference = 1/11
Step-by-step explanation:
S11 = 14 S22 = S11 + 55
11/2 [2a +10d] = 44 = 44 + 55
a + 5d = 4 .......(1) = 99
22/2 [2a + 21d] = 99
2a + 21d = 9 .......(2)
solving (1) & (2)
a = 39/11 , d = 1/11
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