Help me to create a formula in excel.

I have a table in Microsoft excel including the student's name and their marks for the subjects mathematics, English and Accounts. I want a formula in a front column which meets the following criteria.
If marks of each subject are more than 50, column should be displayed as “passed” if not “failed”.
And in another place I want the number of passed and failed student separately.
Can someone tell me a formula?
