It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

what does this picture(rebus) riddle means ?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

What type of tree can I carry in my hand?

How can you make number one disappear by adding something to it?

What four weights can be used to balance from 1 to 30 pounds?