If john has an am radio, but wants to listen to his favorite program on an fm station, will he be able to tune in?   why or why not?  

John will be disappointed.  He will not be able to listen to
his favorite FM station with his AM radio.  There are two
main reasons:

1).  An AM radio is designed to detect changes in the AMPLITUDE
of the radio wavers it receives, and use those changes to create a
sound.  But the amplitude of the FM waves doesn't change. For FM,
their FREQUENCY is what changes, and the AM receiver is not
designed to detect those.

2).  An AM radio is designed to look for stations with frequencies
between 550 KHz and 1700 KHz (in the USA).  But FM stations
transmit at frequencies between  88 MHz and 108 MHz (in the USA). 
John's AM radio simply doesn't listen to those frequencies.