Mr Manson wants to purchase some markers for his new tuition centre. As he is unsure of the number of classes his new tuition centre should have, he decided to purchase markers in multiples of $6$, $8$, $9$ or $15$. He needed to purchsase at least $1000$ markers in total. What is the minimum number of markers that Mr Manson had to purchase? 
Overseas Competition->Knowledge Point->Number Theory Modules->Prime Factorization