** First we will find the LCM of 12,15 and 36**

**By prime Factorisation,**

**12=2*2*3**

**15=5*3**

**36=2*2*3*3**

**Now, LCM= 2**^{2}*3^{2}*5

**We will find that the LCM is 180**

**Now, Largest 5 digit number= 99999**

**Dividing this number by LCM, we get,**

**99999/180=555.5**

**Now we will multiply 180 by 555**

**We will get 99900**

**We will check now and observe,**

**99900/12=8325**

**99900/15=6660**

**99900/36=2775**

**Hence 99900 is the greatest 5 digit number divisible by 12,15 and 36.**