Hi Adele, Welcome to OGN
Mmmmm...I hope this will help you solve the riddle in "Riddle School 2"
Collect all the little tiny grey balls (its actually coins!) Get all 4 of them.
Converse to a guy leaning on the wall with a copy of a music note. Proceed to purchase the whistle from him.
Blow the whistle by clicking on the whistle
You can now exit the classroom now.
Now enter inside Mrs. Sleep's room.
Click on the desk with the top opened. Collect a "slidy" and a 2 coins.
Exit the room and go right, click on the first locker at the right side and collect a 1 coin.
Make a right again and click on the vent below the poster. Click on the "slidy" to take the vent off. Collect the toilet paper roll. Proceed to the left and down to the Men's Room. Pass the person inside the toilet the toilet paper roll and get the mop inside the stall. Exit the Men's room.
Make a left and enter the Janitor's room. Click on the mop when you get in before you click on the talk bubble. You will get enough money for the cookie now. Exit the Janitor's room.
Make a right and proceed to Mr Sum's room. (if u cant get in, follow the instructions below with an Astrix sign.)
Click on the notes on the table and collect a coin. Exit Mr Sum's room.
Proceed to the teacher's Lounge and click
AT THE BACK of the cookie machine, and then plug in the wire.
Now you can buy the cookie and give it to the cookie boy.
Proceed into the office and go into the Mr. Mister's office. Watch the movie which is being played for a while, and proceed all the way left to the entrance. Open the door and you are free.
*Proceed to the teacher's lounge and choose the speech bubble with the " I got permission to....." then click "Mr .O. Boe", you will then exit automatically and go back to Mr Sum's room, you will find Mr Sum there. 
