Question

Alison has 6 yellow discs, 5 blue discs and 9 red discs which she places in a bag. When she draws one disc out, what is the probability that the disc is NOT red?​

Answer 1

Answer:  11/20

explanation:

We know that, Alison has 6 yellow discs, 5 blue discs and 9 red discs

so total he has 6 + 5 + 9 = 20 discs in total

to find the probability of the disc is not red

we have to use the formula :     total disc - red disc / total discs

                                                  20 - 9 / 20

                                               11/20 is the probability of not getting a red disc

OR,

• we can find the probability of getting a red disc :

         =   red disc / total discs

         =    9/20

• now disc is not red = 1 - 9/20

       =     11/20