What you have shown is that the second choice is incorrect. There is at least one value that makes the equation correct (that is, both sides come to the same result.)
If choice two is false then choice one must be true since these results may give the only 2 possible results.
4 different streets with 5 customers on each means 4*5 customers or 20 customers. If he has 20 customers and he gets $10 from each one, thats 20*10. he collected $200