Counting with 2 columns when certain values are entered

I need to count the number of times a column range, say G2:G500 has the value "Y" entered but only when the column range (D2:D500) is entered with the value "N". So the number of times "Y" occurs when column D is equal to "N". something along the lines of: number of occurances when D2:D500 = N and G2:G5000 = Y

quite hard to explain into words ! i hope ive explained it clearly


Thanks for your help