Iwant 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.)

108 ways

Step-by-step explanation:

It is given that there 6 students with Tallest, shortest and 4 medium sized student

back row can be filled with Tallest person and 2 other from 4 medium sized  student (shortest must be in front row)

No of ways in which 2 seats can be filled is

and tallest can take any position out of 3 seats so total no of ways in which last row can be filled is

In front row 3 students can be arranged in 3! ways i.e.

so total ways are

but there are 2 twin which cut the total no of ways to half so total no of ways

108 Ways

Step-by-step explanation:

I did this on AoPs :)

answer:

it is general formula that is used to write value to its excet position

a11 a12 a13

a21 a22 a23

it is the example of order 2 by 3 matrix in this

a11 means value occur in 1 st row 1st column

a12 means value occurs in 1st row 2nd column

a13 means value occur in 1st row and 3rd column

a21 means value occurs in 2nd row and 1st column

a22 means value occurs in 2nd row and in 2nd column

a23 means value occurs in 2nd row and in 3rd column

yes

step-by-step explanation: