Answer:
1) December 11, 2019
Dr Notes receivable 12,000
Cr Sales revenue 12,000
December 31, 2019
Dr Interest receivable 80
Cr Interest revenue 80
February 9, 2020
Dr Cash 12,240
Cr Notes receivable 12,000
Cr Interest revenue 160
Cr Interest receivable 80
2) December 11, 2019
Dr Notes receivable 12,000
Cr Sales revenue 11,764.71
Cr Discount on notes receivable 235.29
December 31, 2019
Dr Discount on notes receivable 78.43
Cr Interest revenue 78.43
February 9, 2020
Dr Cash 12,000
Dr Discount on notes receivable 156.86
Cr Notes receivable 12,000
Cr Interest revenue 156.86