What does this rebus means ?

PROG WORKRESS

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

If an electric train is travelling south, then which way is the smoke going?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

I am 5 letters long.
My first two tell you who I am
My first 3 could be a medicine
My last three reversed could be a young boy.
My 4th, 3rd and 2nd in that order could be a fruit drink.
If you have me you may hang me round your neck
WHAT AM I ?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

What type of tree can I carry in my hand?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?