What is so fragile that saying its name breaks it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

You see me once in June, twice in November, and not at all in May. What am I?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Thomas has missed an excessive number of days of school, so he must meet with Principal Davis. Mr. Davis asks him "Why on Earth have you missed so many days?" Thomas replies "There just isn't enough time for school. I need 8 hours of sleep a day, which adds up to about 122 days a year. Weekends off is 104 days a year. Summer vacation is about 60 days. If I spend about an hour on each meal, that's 3 hours a day or 45 days a year. I need at least 2 hours of exercise and relaxation time each day to stay physically and mentally fit, adding another 30 days. Add all of that up and you get about 361 days. That only leaves 4 days for school." The principal knows Thomas is full of it, but can't figure out why. Where is Thomas going wrong?

In an interview, a boy was asked an unusual question 'How two persons sitting with a table in between them can't see each other?' He was unable to reply. Can you?