Question

If 3+k,18-k,5k+1 are in A.P, then find k​

Answer 1

k=4

Explanation:

Since the given terms are in A.P., the common difference will be the same

So, 18-k-3-k = 5k+1-18+k

15-2k = 6k-17

6k+2k = 17+15

8k = 32

k = 4

Answer 2

Given:

• 3 + k , 18 - k and 5k + 1 are in AP .

To find :

• The value of K .

Solution :

• As we know that, In AP common difference is same :

• b - a = c - b

=> 2b = a + c

Here ,

• a = 3 + k

• b = 18 - k

• c = 5k + 1

=> 2 ( 18 - k ) = 3 + k + 5k + 1.

=> 36 - 2k = 4 + 6k

=> 36 - 4 = 6k + 2k

=> 32 = 8k

=> k = 32/8

=> k = 4

Hence , the value of k is 4.