Skip to main contentSkip to solution

If A and B are square matrices of order 3 such that ∣A∣=2|A| = 2, ∣B∣=3|B| = 3, and ∣2A⋅adj(3(adjB))∣=2α⋅3β|2A \cdot \text{adj}(3(\text{adj}B))| = 2^\alpha \cdot 3^\beta, then value of α+β\alpha + \beta is:

Solution

✅ Correct Option: 3

For 3x3 matrices: ∣adjB∣=∣B∣2=9|adj B| = |B|^2 = 9. ∣3⋅adjB∣=33⋅9=243=35|3 \cdot adj B| = 3^3 \cdot 9 = 243 = 3^5. ∣adj(3⋅adjB)∣=(35)2=310|adj(3 \cdot adj B)| = (3^5)^2 = 3^{10}. ∣2A∣=23⋅2=24|2A| = 2^3 \cdot 2 = 2^4. So ∣2A⋅adj(3⋅adjB)∣=24⋅310|2A \cdot adj(3 \cdot adj B)| = 2^4 \cdot 3^{10}. Hence α+β=4+10=14\alpha + \beta = 4 + 10 = 14.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question