The LMTD in deg C is

Question

Air enters a counter flow HE at 70⁰C and leaves at 40⁰C. Water enters at 30⁰C and leaves at 50⁰C. the LMTD in deg C is                                                                                                                                                                                           

      (a) 5.65                                                               (b) 14.43

      (c) 19.52                                                             (d) 20.17