Problema Solution
The chart shows decibel levels of different sounds. The difference of 3 times the decibel level of city trafic and 67 is the decibel of a blue whale. What is the decebel of city trafic?
Normal 60 db
Football Stadium 117db
Blue Whale 188 db
Answer provided by our tutors
Let 'x' be the decibel level of city traffic and 'b' be the decibel level of a blue whale.
Since the Normal db sound is 60 and Football Stadium is 117, the db of the city traffic would be somewhere in between that is
60 < x < 117 /*3
180 < 3*x < 351
Then we have 3*x - 67 = b. We need to find x.
b = 188 db the decibel level of a blue whale so we have
3*x - 67 = 188
3*x = 188 + 67
x = 255/3
x = 83 db and 80 < 83 < 117 so this the solution of the problem.
The city traffic is 83 db.