Would anyone check my solutions to a few probability questions (1 Viewer)

[kpad5991]

https://imgur.com/gallery/w3DX7QV

Please can you check through my solutions and see what mistakes I’m making. I must admit 17b I had no clue

 

[HeroWise]

Working out for 17 a , in the HSC requires this step

the ensures you get any card and the is any other specific card

17 b is



Uses binomials

 

[HeroWise]

For 18

Count all the yellows and the blue only once you should get 11 total outcomes. I understand in you thinking its from the total set but if u think about it the question is talking about "atleast 3" only.

 

[kpad5991]

For 18

Count all the yellows and the blue only once you should get 11 total outcomes. I understand in you thinking its from the total set but if u think about it the question is talking about "atleast 3" only.

Are the others correct?