Its very good puzzle. It is simple but still its effective to confuse peple to scratch her heads. Here is the puzzle: We have total 100 rs and we need to buy exactly 100 birds. The prizelist for birds is as follow: 1) 1 parrot = 5 rs 2) 1 craw = 1 rs 3) 20 sparrows = 1 rs But you have to follow these conditions -> you have to spent all 100 rs. -> you have to buy exact 100 birds -> you have to buy all three birds. That mean you cant buy any specific kind of bird. So you must have all three kind of bird when you finish the buying!!!! Lets hit it CEans!!!!