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If A is semy square matrix of order 3 an...

If A is semy square matrix of order 3 and det A = 5, then what is det`[(2A)^(-1)]` equal to ?

A

`1//10`

B

`2//5`

C

`8//5`

D

`1//40`

Text Solution

Verified by Experts

The correct Answer is:
D
`|A|=5 rArr |2A|=2^(3)xx5=40`
`rArr |A^(-1)|=(1)/(|A|)rArr|(2A)^(-1)|=(1)/(|2A|)=(1)/(40)`
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