[" 50.A man "x" can hear only upto "10kH" and another man y upto "20kH" .A note of frequency "],[500Hz" is produced before them from a stretched string.Then "],[" a) Both will hear sounds of same pirch but different quality "],[" b) Both will hear sounds of different pitch but same quality "],[" c) Both will hear sounds of different pitch and different quality "],[" d) Both will hear sounds of same pitch and same quality "]