Quiz Night (Round 2)

Quiz Night

Round 2

Multiple Choice

A teacher writes six words on a board: “cat dog has max dim tag.” She gives three students, Albert, Bernard and Cheryl each a piece of paper with one letter from one of the words. Then she asks, “Albert, do you know the word?” Albert immediately replies yes. She asks, “Bernard, do you know the word?” He thinks for a moment and replies yes. Then she asks Cheryl the same question. She thinks and then replies yes. What is the word?

• cat

• dog

• has

• max

• dim

Multiple Choice

There are 100 doors in a row. They all are initially closed. A person walks through all the doors 100 times and toggles the state of some specific doors every time. That means if the door is closed, he will open it and if its opened then he will close it.

In each walk he selects specific doors to toggle, in the following manner. In his first walk, he toggles all the doors in multiple of 1 that means he toggles all the 100 doors. In the second walk, he toggles the doors in multiple of 2. In the third walk, he toggles the doors in multiple of 3 that means, he will change the state of door no.3, 6, 9, 12... and so on. In the fourth walk he toggles doors in multiple of 4 and so on...

This way he walks for 100 times.

The puzzle is : What door number out of the following will remain opened after 100 walks.

• 23

• 24

• 25

• 26