Question

On a workday the average decibel level of a busy street is 69 db, with 139 cars passing a given point every minute. if the number of cars is reduced to 17 cars every minute on a weekend, what is the decibel level of the street? answer in units of db.

Answer 1

Decibel is directly proportional to number of cars passing the point. That is,

69 db ----- 139 cars
x   db ----- 17 cars

x = number of cars passing the point per minute on a weekend.

Then,
x= (69*17)/139 = 8.43 db ≈ 8 db