Question

The total number of $4$-digit numbers whose greatest common divisor with $54$ is $2$, is _____.

Answer 1

Answer: 3000

$N$ should be divisible by 2 but not by 3
$N=$ (Numbers divisible by 2 ) $-$ (Numbers divisible by 6$)$
$N=\frac{9000}{2}-\frac{9000}{6}=4500-1500=3000$