Answer: No, the scenario won't earn you enough money
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Step-by-step explanation:
You work 4 hours with your uncle, at $8 an hour, so that means you earn 4*8 = 32 dollars.
You work 12 hours online, at $4 an hour, so you earn 12*4 = 48 dollars.
In total, you earn 32+48 = 80 dollars overall when combining the two lines of work.
The total 80 is smaller than 120, so this scenario isn't possible if you want to aim for $120 or more. You'll need to work more hours somehow.