Answer:
The answer is "24 elements"
Step-by-step explanation:
Please find the complete question in the attached file.
Given that:
[tex]\to Enrique=E\\\\ \to Katie=K \\\\\to Rihanna=R \\\\\to Bruno=B\\\\[/tex]
The element in space are:
[tex]EKRB , ERKB , ERBK , EKBR , EBKR , EBRK , KERB , KEBR , KREB , KRBE ,\\\\ KBRE , KBER , RKEB , RKBE , RBKE , RBEK , REBK , REKB , BEKR , BERK ,\\\\ BREK ,BRKE , BKRE , BKER[/tex]