1. Tardigrade
  2. Question
  3. Mathematics
  4. 7 digits from the number 1, 2, 3, 4, 5, 6, 7, 8, 9 are written in a random order (without repetation). The chance that the 7 digit number is divisible by 9 is :

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. 7 digits from the number $1, 2, 3, 4, 5, 6, 7, 8, 9$ are written in a random order (without repetation). The chance that the 7 digit number is divisible by 9 is :

Probability - Part 2

Solution:

$n ( S )={ }^9 C _7 \cdot 7 !$
$n ( A )=4 \cdot 7 !$
$\frac{4 \cdot 7 !}{{ }^9 C _7 \cdot 7 !}=\frac{4}{36}$
$\therefore P ( A )=\frac{4}{36}=\frac{1}{9}$