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If A is m * n matrix such that AB & BA both are defined, then B is a matrix of order

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ISRO LPSC Technical Assistant Mechanical 23 Feb 2020 Official Paper
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  1. n * n
  2. m * m
  3. m * n
  4. n * m

Answer (Detailed Solution Below)

Option 4 : n * m
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Detailed Solution

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Concept:

Two matrices Am × n and Bp × q 

if AB and BA are defined then p = n and q = m

Calculation:

Given:

AB and BA are defined.

so the order of the matrix B is Bn × m

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