Question 613252
There is a combination lock with 4 numbers, 2 of the numbers must be: 1, 2 or 3 and the other 2 numbers must be: 6, 7 or 8. Write an equation to show the total number of combinations. 
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# of possible combiinations = (3C2)(3C2) = 3*3 = 9
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Cheers,
Stan H.