X - y = 5
y = x - 5
For domain {0, 2, 4}, range = {0 - 5, 2 - 5, 4 - 5} = {-5, -3, -1}
Umm i answer is looking 134
18 choose 7
=C(18,7)
=18!/(7!(18-7)!)
=31824
OR
18 choices for first passenger,
17 choices for second passenger,
....
12 choices for 7th passenger,
so total = 18*17*16...12
but there are 7! ways to order the 7 passengers, so
number of groups
=18*17*16...12/7!
=31824 as well
It is 1
70+30*1=100, which is not a prime number