Please help me. Explanation needed.

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

What describes horizontal cross section of the right rectangle 6m 8m 5m