Question

For what value of k are 2k, k + 10 and 3k + 2 are in A.P.
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Answer 1

2k, k + 10, 3k + 2 in A.P.

so, (k + 10) - 2k = (3k + 2) - (k + 10)

2k + (3k + 2) = 2 × (k + 10)

5k + 2 = 2k + 20

3k = 18

k = 6

Answer 2

Answer:

let a=2k and a2=k+10

d=k+10-2k=10-k

d=3k+2-k-10=2k-8

so 2k-8=10-k

2k+k=10+8

3k=18

k=6

hence the result