36
Not sure what a strait line is! Five people can stand in a straight line, with Jessie third in 24 ways if you ignore left-to-right and right-to-left "reflections".
128
There are 7 people who could stand first, with 6 people who could stand second for each of those first people, with 5 people who could stand third for each of those first two people, and so on, until with 1 person left who could stand seventh for each of the first six people. This gives 7 × 6 × 5 × ... × 1 = 5040 ways.
24 ways
There are n! (n factorial) ways that n people can stand in line. So six people can stand in line in: 1*2*3*4*5*6 = 720 different ways
36
If the people are always facing forward? 24 ways.
Not sure what a strait line is! Five people can stand in a straight line, with Jessie third in 24 ways if you ignore left-to-right and right-to-left "reflections".
128
4*3*2*1 = 24 ways.
There are 7 people who could stand first, with 6 people who could stand second for each of those first people, with 5 people who could stand third for each of those first two people, and so on, until with 1 person left who could stand seventh for each of the first six people. This gives 7 × 6 × 5 × ... × 1 = 5040 ways.
I make it 136 ways.
24 ways
10 people can line up in (10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2) = 3,628,800 different ways.
720
6! = 720