Correct Answer: 7

Solution : Given:
1. he is waiting ⇒ 269
2. she is ready ⇒ 915
3. he and she ⇒ 271

By comparing all the above-coded sentences, we find that –
In sentences 1 and 2, is is a common word and 9 is a common code.
In sentences 1 and 3, he is a common word and 2 is a common code.
In sentences 2 and 3, she is a common word and 1 is a common code.
The remaining words and codes in sentence 1 are waiting and 6 , and in the sentence 2 are ready and 5 . In sentence 3 are and and 7.
Finally, is → 9 ; he → 2 ; she → 1 ; waiting → 6 ; ready → 5 ; and → 7

So, and will be coded as 7 . Hence, the third option is correct.