Nurse Ranji has worked more night shifts in a row than Nurse Lalita, who has worked five. Nurse Sunita has worked fifteen night shifts in a row, more than Nurses Rajni and Lalita combined. Nurse Anita has worked eight night shifts in a row, less than Nurse Rajni. How many night shifts in a row has Nurse Rajni Worked?

Nurse Rajni $>$ Nurse Lalita $(5)$ Nurse Sunita $=15$, which is more than Nurse Rajni and Lalita combined. Nurse Anita $=8$, LESS than Nurse Rajni. So, Nurse Rajni must have worked more than $8$ but less than $10$ night shifts, since $10+5$ would be $15$, but they haven't worked as many night shifts as Nurse Sunita. Hence, Nurse Rajni has worked $9$ night shifts. In the actual exam, Rajni was misspelt as Ranji at the beginning, we have kept the mistake to give you a realistic experience of the exam.