$6=2\times3, 9=3\times3, 2\times3\times3\times5=90$. The number of students is a multiple of 90. $180\div90=2$. 
Ms Lee has many students. They can be split into $$5$$ groups, $$6$$ groups or $$9$$ groups equally. How many students might she possibly have? 
(1) $$120$$ 
(2) $$150$$ 
(3) $$180$$ 
(4) $$240$$ 
(5) $$300$$ 