system/bin permissions?

[actngrezy]

I was just wondering in root explorer I was trying to change the system/bin folder permissions to 755.
Now in root explorer it currently has under user all boxes check under group the read and execute boxes are checked and under others the read and execute boxes are checked.
Now in order to make that 755 which boes need to be checked and unchecked or is there an adb command to do this?

Edit i think I got it
su
mount -o remount,rw -t yaffs2 /dev/block/mtdblock4 /system
chmod 755 /system/bin
mount -o ro,remount -t yaffs2 /dev/block/mtdblock4 /system

would this be it??