Please, give me hints, I've no idea ;):
Find greatest number $x$ such that $x<1000$ and $x$ divided by $4$ gives remainder $3$, divided by $5$ gives remainder $4$, and divided by $6$ gives remainder $5$.
I already know that for some natural $a, b, c$, $x=4a+3=5b+4=6c+5$, but what next? Help please.