Permutation Combination Question 11
Question 11 - 29 January - Shift 2
The total number of 4-digit numbers whose greatest common divisor with 54 is 2 , is ________
Show Answer
Answer: 3000
Solution:
Formula: Non-Consecutive Selection
$N$ should be divisible by 2 but not by 3
$N=($ Numbers divisible by 2$)-($ Numbers divisible by 6 )
$N=\frac{9000}{2}-\frac{9000}{6}=4500-1500=3000$
