Thomas has two bags of pens.
In the first bag there are 3 blue pens and 7 black pens.
In the second bag there are 2 blue pens and 4 black pens.
Thomas takes at random a pen from the first bag.
He then takes at random a pen from the second bag.
a.[2]
Complete the probability tree diagram.
b.[2]
Work out the probability that Thomas takes two black pens.
Probability Trees Questions
Practise OCR GCSE Maths Probability Trees with exam-style questions for Foundation and Higher tier. 40 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.