You can put this solution on YOUR website! This is a problem of converting units.
First of all, forget about any numbers.
Just write an expression with units only.
Units are hours, yards, dollars, days, miles/hours, etc.
In this problem,
(months)*(days/month) = days
All months don't have 30 days, but it's a common estimate
Now write it with numbers: months x days/month = days