Answer:
18
Step-by-step explanation:
Since, k + 9, 2k -1 and 2k + 7 are the consecutive terms of an A.P.
Therefore, their common differences would be same.
Hence,
(2k - 1) - (k + 9) = (2k + 7) - (2k - 1)
2k - 1 - k - 9 = 2k + 7 - 2k + 1
k - 10 = 8
k = 8 + 10
k = 18
