Final answer:
The sum of -121 1/2 and 41 1/2 is -80. The difference between -0.35 and -0.25 is -0.1. Thus, the correct answer is option 3: a. -80, b. 0.1.
Step-by-step explanation:
The question requires us to solve two arithmetic operations:
- Adding -121 1/2 and 41 1/2.
- Finding the difference between -0.35 and -0.25.
Let's solve each part step-by-step.
- For part a, when we add -121 1/2 (+ -121.5) and 41 1/2 (+ 41.5), we subtract 121.5 from 41.5 to get -80, because adding a positive number to a negative number of larger magnitude results in a negative number.
- For part b, when finding the difference between -0.35 and -0.25, we actually add the opposite of -0.25, which is +0.25, to -0.35. This results in -0.10 or simply -0.1, as negative minus a negative is the same as adding the positive equivalent.
Therefore, the correct answer is option 3: a. -80, b. 0.1.