Xiaoming buys one vegetarian dish and two vegetarian dishes, with different collocation methods = 2 *4 =8 (a vegetarian dish has two choices and four vegetarian dishes, so it is multiplied).

Xiaohong buys two vegetarian dishes, two vegetarian dishes, and different collocation methods = 1*3*4/2 =6 (there are 1 methods for choosing vegetarian dishes, the first one has four kinds, and the second one has three kinds, because there is a problem in the order of the two, so it is repeated to choose B first and then A, so it should be divided by 2).

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