### Question: Mrs. Lacson harvested 80 sweet potatoes. She sold 20 of them to Mrs.  Adams and 15 of them to Mr. Lenon. How many sweet potatoes are not yet sold?
### Answer: Mrs. Lacson sold a total of 20 + 15 = <<20+15=35>>35 sweet potatoes.
Hence, there are still 80 - 35 = <<80-35=45>>45 sweet potatoes left unsold.
#### 45