Excel - SUMPRODUCT Formula / How to Count Cells According to Multiple Criteria

While using Excel, sometimes we need to count some cells which have special qualitatives. 

Excel can count all the cells which included an important number for us, a text which special for us...

An Example: 

If you want to know how many "yellow" cells are "glass 4mm", just write this code: 

=SUMPRODUCT((C3:C16="Yellow")*(B3:B16="Glass 4mm"))

If you want to know how many "black" glasses have 20 or less quantity, this code is for you: 

=SUMPRODUCT((C3:C16="Black")*(D3:D16>=20))

If you want to know how many products is less than 20 and cheaper or equal to 100$, this is the code: 

=SUMPRODUCT((E4:E16<=100)*(D4:D16<=20))

These samples can be reproduced. You just need to write suitable code for your scenario.