Final answer:
The correct estimated difference in value between 100 units of currency A and 300 units of currency B, where 1 unit of currency B equals 0.077 units of currency A, should be approximately 77 units of currency A. However, this answer is not listed in the provided options, suggesting there may be a need for clarification.
Step-by-step explanation:
To estimate the difference in value between 100 units of currency A and 300 units of currency B, given that 1 unit of currency B is worth approximately 0.077 units of currency A:
- First, convert the units of currency B into currency A equivalent: 300 units of currency B × 0.077 units of currency A/unit of currency B = 23.1 units of currency A.
- Then, calculate the difference in value between the two currencies: 100 units of currency A - 23.1 units of currency A = 76.9 units of currency A.
- Since we are estimating, the closest estimate provided in the options to 76.9 units of currency A is 77 units of currency A, which is not listed in the options provided. Therefore, we may need additional clarification as the provided answers do not reflect the estimated calculation.