Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Mrs. Young buys a 300 piece puzzle set for her three sons.  She divides the pieces evenly to the three boys.  Reyn can place 25 pieces into the puzzle picture.  Rhys places twice as much as Reyn.  Rory places three times as much as Reyn. Altogether, how many puzzle pieces are still left to be placed?

### Response:
Reyn places 25 pieces.
Rhys places 2*25 = <<2*25=50>>50 pieces.
Rory places 3*25 = <<3*25=75>>75 pieces.
All three boys place 25+50+75 = <<25+50+75=150>>150 pieces.
There are 300-150 = <<300-150=150>>150 pieces still left to be placed.
#### 150