Question

In the case of the previous question how many rooms will be closed in all?

• A. 513
• B. 31
• C. 13
• D. 315

Answer 1

Answer: (A)

513

Number of perfect squares in between $1$ to $500$ are $22$

and the number of perfect squares between $501$ to $1000$ are $9$ [from $23$ to $31$]

$\therefore$ Total number of closed rooms in last question=Number of closed rooms from $1$ to $500$+ Number of closed rooms from $501$ to $1000$

$=22+(500-9)$

$=513$