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I want to take a picture of my six friends standing in two horizontal rows of three. How many different photos can I take if the tallest person must stand in the back row, the shortest person must stand in the front row, and two of my friends are identical twins whom I can't tell apart? (The identical twins are neither the tallest nor the shortest.)

 Dec 23, 2019
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This may be incorrect, but I'll give it a try.

The tallest person is in the back row, with three spots. 3 ways to place him. The shortest person stays in the front row, 3 ways to place him. Normally, our answer would just be 3*3*4! (4! means 4*3*2*1) but two friends are identical twins, so they are indistinguishable. Therefore our answer is (3*3*4!)/(2!) = 108. 

Hope this helped!

laugh

 Dec 23, 2019

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