Help please...CFAI mock morning session Q 15

CFA Level II
#1

How did they the balance without knowing the monthly payment? How did they calc P&I or Principal? I really don’t get it…

#2

n=243 I/Y=4.8/12 PV=117.74 FV=0

calculate PMT

#3

Gotcha…Thanks! Feel like my brain is in a mess. Can’t put everything together…