(1) solution: This is equivalent to arranging 12 identical balls in a row and then dividing them into 4 parts by interpolation. 1 The plug board has 1 1 plugs, the second plug board has 10 plugs, and the third plug board has 9 plugs. According to the principle of multiplication, it can be divided into11*10 * 9 = 990 kinds of division. There are 990 solutions. (2) Solution: 10 stairs, spanning 7 steps. From the topic, there must be 3 times to cross the second order and 4 times to cross 1 order, which is equivalent to three consecutive identical white balls and four identical red balls. Through several methods. Arrange four red balls first, there is an arrangement method, and then arrange the remaining three white balls with (5*6*7)/3! =35 permutations. That is, there are 35 ways to cross. C(7，3)=7！ /(3! *4! Therefore, the teacher is right, "I love my teacher, and I love the truth more". Quarrel is ok, but pay attention to the way.