Question
Number of integers $x$ between $1$ and $95$ such that $96$ divides $60x$ is -:
$A$. $0$
$B$. $7$
$C$. $8$
$D$. $11$
My Approach
For $a$ divides $b$, we can write as-:
$a \,\, |\,\,b \Rightarrow b=a \times c $,for some integer $c$
so
$96 \,\, |\,\,60x \Rightarrow 60x=96 \times c $
now putting option one by one
$x=7,$
$60 \times 7=96 \times c $ $c=\frac{420}{96}=4.375$ hence not possible as $c$ is an integer.
$x=8,$
$60 \times 8=96 \times c $ $c=\frac{480}{96}=5$ possible as $c$ is an integer.
$x=11,$
$60 \times 11=96 \times c $ $c=\frac{660}{96}=6.875$
not possible as $c$ is an integer.
hence $8$ should be the answer .is my reasoning correct? Please help
$60x$ is divisible by $96$ $\Rightarrow \frac{60x}{96}$ is a natural number
$\Rightarrow \frac{12\times 5x}{12 \times 8}$ is a natural number
$\Rightarrow \frac{5x}{8}$ is a natural number
$\Rightarrow x$ is divisible by $8$ because $GCD(5;8)=1$.
From $1$ to $95$, there are $11$ numbers satisfy this: $8;16;24;32;40;48;56;64;72;80;88$.