they structured the question incorrectly....both walkie talkie and telephone would be correct. this is because they didnt say whether it is half or full duplex.... therefore if they had said 'half duplex' the answer would have been walkie talkie, and if they had said 'full duplex' the answer would have been telephone..... however they didnt say half nor full duplex, they said 'duplex'---- so there are 2 answers
this is paper 1, any explanation really isn't needed at this part as much as for paper 2. i'm sure most of us just want to get the answers quickly rather than a long explanatory session.
well, anuh everybody love boring teaching, if yuh have a problem guh somewhere else. cause uh na acknowledge seh him actually a help, uh just big nd miserable nosa