[填空题]
A lego storage box is left with 4 blue and 7 red br:bf 3; sof*jgikh11uf/7qcsiq ,(w*blkwf: l icks. Max takes a brick from 3w u1;hkf,s:1fb b7(lf:q f*owi g* kj/ilqcstd c;)zqf:n* 7by fccoi)x- -ythe box at random and attaches it to his new castle. He then choos:o ;nybc ))x--iztffcc7yq*des another brick fron the same box at random.
1.Complete the following tree diagram.
2.Calculate the probability that both bricks chosen by Max are of the same color.≈
