Coins and a Table

[chetjan]

Here is a hard or easy problem depending on how you see it. If get how to solve it will be too easy, otherwise it might be impossible.

100 identical coins have their center on a rectangular table so that no more can be placed without overlap. Prove that you can cover the table with 400 coins. (This time overlap is allowed.)

[Math Tutor]

Very difficult problem.
I cannot solve it.

[sabah orou]

Here is a hard or easy problem depending on how you see it. If get how to solve it will be too easy, otherwise it might be impossible.

100 identical coins have their center on a rectangular table so that no more can be placed without overlap. Prove that you can cover the table with 400 coins. (This time overlap is allowed.)

Solution : Suppose the sides of the rectangular table are X & Y

Area would be (X) x (Y) = 100

Now if we overlap each coin,we will have the new side as 2X & 2Y

Area wil be (2X) x (2Y) = 4 XY = 4x 100
= 400