Inverse function equation

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).

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

What is 1.5% of 120 or what number is 1.5% of 120