What day of the week is the first day of the month?

The last Friday of a particular month is on the 25th day of the month. What day of the week is the first day of the month?

Counting back from 25th day, the multiple of 7 is 21'st day which will also be a Friday. i.e; 25-21= 4th day of the month.

If 4th day is a Friday, then first day of month will be Tuesday.

The first day of the month is a Tuesday.