Answer:
Assignments finished = 7
Step-by-step explanation:
Given that:
Time taken for one assignment = 20 minutes
Time spent on working = 2 hours 20 minutes
2 hours = 120 minutes
Time spent on working = 120 + 20 = 140 minutes
Number of assignments = 
Number of assignments = 
Number of assignments = 7
Hence,
Assignments finished = 7
Exchange rates help you know how much your currency is worth in a foreign currency.