Meaning: an informal expression meaning something that is easy to do. A trivial matter

Example:
1.- If you practise enough, driving will eventually become child's play.
2.- The hike that we did this weekend was child's play. I am looking forward to something a bit more challenging.

Meaning: the particular situation in which one cannot win.

Example:
I couldn't start my own business, until I have got money, and I couldn't get money until I start my own business, oh my God, this is the real catch-22 situation.

Meaning: do or say something that causes trouble and make a lot of people angry or worried.

Example:
The information of deducting 15% of salary packages of all the employees of York Electronics company set the cat among the pigeons and many employees started resigning immediately and joining the competitor company.

Meaning: trifle with, toy with, confuse somebody.

Example:
1. It's just the newest trap in the everlasting cat and mouse game between the guards and thieves.
2. Don't play cat and mouse with that little child.