Joey works at the airport repairing airplane engines, where the decibel level can reach over 100 db. wearing protective earwear, the decibel level reacing joey's ear only reaches 80 db. how many times less intense is the sound with his ear protection when compared to no protection?

You find a mysterious, dull substance on the ground and pick it up for a closer look. it is powdery, very light, and soft to the touch. the substance is most likely i. an organic mineral ii. a metallic mineral iii. a nonmetallic mineral i only ii only iii only i and ii i and iii