Question

If a , b , c are three vectors such that $[ a\,b\,c]= 5$ then the value of $[a \times b , \times c , \,c \times a]$ is :

• A. 10
• B. 15
• C. 25
• D. 20

Answer 1

Answer: (C)

25

Answer 2

Given,
$[ a , b , c ]=5$
We OW,
$[ a \times b \,b \times c\, c \times a ]=[ a , b , c ]^{2}$
$\therefore \,[ a \times b\, b \times c\, c \times a ]=(5)^{2}=25$