I need help... plz help....

C.  Caitlin can eliminate $54 from Food/Clothes and $120 from Entertainment.
Monthly Amortization to payoff balance
Amortization computation
A = [P (r(1+r)^n)] / ((1+r)^n-1) 
where:
P = $4880
r = APR/12
  = 16%/12
  =  1.33%
n = 20 months
A =$279.498 
Amortization deficit = Required Amortization - Minimum amortization
Caitlin's Amortization deficit = $279.50-$105.86
                                             = $173.64 round off to $174

c. $54 Food + $120 Entertainment = $174 deficit