Respuesta :

Answer:

  1. 84 ways
  2. 3,780 numbers
  3. 3,628,800 ways

Step-by-step explanation:

Solving :

Q1

  • No. of ways to choose 6 from 9 :
  • ⁹C₆ = 9! / 6! 3!
  • 9 x 8 x 7 x 6! / 6! x 3 x 2
  • 3 x 4 x 7
  • 28 x 3
  • 84 ways

Q2

  • No. of numbers with distinguishable digits :
  • 9! / 4! 2! 2!
  • 9 x 8 x 7 x 6 x 5 x 4! / 4! x 2 x 2
  • 9 x 2 x 7 x 6 x 5
  • 10 x 63 x 6
  • 378 x 10
  • 3,780 numbers

Q3

  • No. of ways to arrange :
  • 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2
  • 90 x 56 x 30 x 24
  • 5040 x 720
  • 3,628,800 ways