Question 1168171
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The first team (boy,girl) can be arranged in 7*5 = 35 ways.


After that, the second team (boy,girl) can be arranged in 6*4 = 24 ways.


Such teams can be combined in  {{{(35*24)/2}}} = 35*12 = 420 different ways for a game.    <U>ANSWER</U>
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Solved.