Which of the following numbers will replace the question mark (?) in the given series?
165, ?, 195, 210, 225, 240

Correct option is A

Series: 165, ?, 195, 210, 225, 240
The difference between consecutive terms in the sequence we have:
195−?
210−195=15
225−210=15
240−225=15
We can observe that the series increases by 15 with each term after the missing number.
So, to find the missing number, we can subtract 15 from 195:
195−15=180
Correct answer: (a) 180.