Answer:
Total loudness of earphones will be 11176 decibels
Explanation:
We have given the ratio of loudness of earphones of Lana's , Polina's and Goffy's are 6:5:3
Let the loudness is multiple of x
So ratio will become 6x:5x:3x
So total = 6x+5x+3x = 14x
As it is given Polina's earphone loudness is 420 decibels
So [tex]5x=420[/tex]
x = 84 decibels
So total loudness of earphones will be = 14×84 = 1176 decibels