Question: how to get all the gems in luigi's mansion 3 b1?
Answer: Red Gem. Go to the far left of the parking lot until you reach an electrical meter. ... 
Blue Gem. Go in the opposite direction to the garage, at the very far right. ... 
Green Gem. When you leave the garage, pass the door on the far left to reach the laundry room. ... 
Purple Gem. ... 
Yellow Gem.