6nco3 + 9o = ?

Put your answer in simplest form.

Let us assume the total number of students surveyed = x

Then

Number of students preferring red = x/4

Number of students preferring blue = x/8

Then

Number of students remaining = x - [(x/4) + (x/8)]

                                                  =x - [(2x + x)/8)

                                                  = x - (3x/8)

                                                  = (8x - 3x)/8

                                                  = 5x/8

Number of students preferring the color green = (3/5) * (5x/8)

                                                                          = 3x/8

We also know that the total number of students preferring the color green is 15

So

3x/8 = 15

3x = 15 * 8

x = (15 * 8)/3

  = 5 * 8

  = 40

So in total 40 students were surveyed. I hope the procedure is clear to you.

Step-by-step explanation: