General questions regarding OFDM modulation In Orthogonal frequency division multiplexing (OFDM), data symbols are modulated using an N pt-IFFT operation to produce ONE output OFDM 

Assume we have total of $N$ QAM symbols which are input to the IDFT operation.

1) Is the output time domain samples $X_k$ also of length $N$ in length? 

2) If ONE data QAM symbol has symbol duration $T$, is ONE OFDM symbol of symbol duration $T$ or is one SAMPLE of the OFDM symbol of duration $T$?

Thanks looking forward for your answers

Update 

One example of OFDM modulator is the one used in LTE, in particular the subcarrier bandwidth is 15 KHz, and the OFDM symbol (and not one sample of the OFDM symbol) is 1/15k = 66.67 $\mu $ sec which is equal to the transmission time of one symbol (for example 1 QAM) over one subarrier. If my understanding is correct than the answer provided below is wrong. Can somoeone please double check?

Thanks
The output time domain samples are also of same length $N$. Your figure shows a part of a OFDM receiver. At the OFDM transmitter, IFFT is used. 
One OFDM symbol duration is $NT$ and obviously one sample of the OFDM symbol has a duration $T$.