Skip to main contentSkip to solution

The number of all possible matrices of order 2×22 \times 2 with each entry 0 or 1 having their determinants as positive value is :

Solution

✅ Correct Option: 1

With entries 00 or 11, ad−bcad-bc can only be −1-1, 00 or 11, so positive means ad−bc=1ad-bc=1. This forces ad=1ad=1 and bc=0bc=0, i.e. a=d=1a=d=1 with (b,c)(b,c) being (0,0)(0,0), (0,1)(0,1) or (1,0)(1,0): exactly 33 matrices.

Keyboard Shortcuts

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