Hola, buenas noches. Alguíen podria ayudarme(? es urgente x, d​

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).

Three coins are flipped. what is the probability that there will be at least two tails?

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?