SOUND The loudness of a sound L in decibels is defined by L= 10 log. R, where R is the relative intensity of the sound. A chofr director wants to determine how many members could sing while maintaining a safe level of sound, about 80 decibels. If one person has a relative intensity of 10 when singing, then how many people could sing with the same relative intensity to achieve a loudness of 80 decibels?

what graph

step-by-step explanation:

ratio is 2 : 9

the answer is three

13.5 : 3

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.