GCSE Maths Question

https://www.elevise.co.uk/kx22q.html

Hey! Does anyone have any advice on how to tackle this one? I did take a look at the answer provided above, but I have no idea what I’m doing.

Thanks a lot!

Reply 1

mqb2766

Original post by crochetingduck

https://www.elevise.co.uk/kx22q.html

Hey! Does anyone have any advice on how to tackle this one? I did take a look at the answer provided above, but I have no idea what I’m doing.

Thanks a lot!

Which part are you unsure about? You have the two basic equations (definitions of probability) so
g / (r+g) = 3/7
and
(g+3)/(r+g+5) = 6/13
Then its just a case of solving them simultaneously.

Or you can do a bit of working to simplify the algebra a bit so as noted you could think of the first one as
g/r = 3/4
which means you can substitute into the second.

(edited 2 months ago)

Reply 2

xxxxx1241242141

Original post by crochetingduck

https://www.elevise.co.uk/kx22q.html

Hey! Does anyone have any advice on how to tackle this one? I did take a look at the answer provided above, but I have no idea what I’m doing.

Thanks a lot!

Draw a probability tree and see what you can discover, remember each branch must add up to 1. Let me know if you need more guidance on what to do next