Find the invalid no.from the following series 13, 18, 25, 30, 37, 40\nOptions:\n(A) 30\n(B) 35\n(C) 40\n(D) 47\n(E) 50
Stream of thoughts:
(C)
The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5.

So, 40 is wrong.

.

So, the answer is (C)