1: Unbeliever attending robbery (7)
2: 'Ransom'? Lame. Run 'Rocky I', 'II', 'III', etc. (5,8)
3: Genuine assistance for the auditor is passed on (7)
4: Chump getting past in chasm (5)
5: A muskmelon or cola nut pa sliced (9)
6: Incredibly stoned, taking Intro to Math final (7)
7: See why a convertible is nonsense (7)
10: Fling an item of furniture (3,5,5)
14: Manipulated miter gear to move again (9)
16: A fool had peas cooked (7)
17: Closest home receives attention (7)
19: Declare exam if I am reported (7)
20: Sally was ready to embrace East German (7)