How many ways can eight letters be arranged into groups of five where order matters and the first two letters are already chosen ?

a 100
b 120
c 240
d 720

120

Step-by-step explanation:

Think about the eight letters A B C D E F G H, if A and B (or any two letters) are already chosen then you want to know how many ways 6 letters can fill 3 spaces when order matters, in other words the letters F G H are considered 1 outcome with the first two letters and G F H is considered another individual outcome with the first two letters.  If order didn't matter then F G H and G F H with the first two letters would be considered only one outcome.

answer: the value of x is 7cm

step-by-step explanation: