Sarah has two boxes of marbles, Box A and Box B.
There are 4 green marbles and 2 yellow marbles in Box A.
There are 3 green marbles and 7 yellow marbles in Box B.
Sarah takes at random a marble from each box.
Complete the probability tree diagram.

Work out the probability that Sarah takes two green marbles.
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.