Execute would be 744 (remember, it is a octal-code: 4 means read, 2 means write, 1 means execute, written as bits it is 100 for read, 010 for write and 001 for execute, for the resulting rights they are combined by logical "or" ), the first octet is the owner, the second the group, the third "others"
Owner octet 6 = 4+2 = read + write
Group octet 4 = read
others octet 4 = read
execute bit set on directory means: can enter directory
For a complete description see https://en.wikipedia.org/wiki/File_syst ... c_notation