Final answer:
The expression 0.10y in the equation V = 0.25x + 0.10y represents the total value of the dimes that Amy has.
Step-by-step explanation:
The expression 0.10y most likely represents the total value of the dimes Amy has. Each dime is worth 10 cents (0.10 dollars), so y dimes would have a value of 0.10 multiplied by y, which gives us the expression 0.10y. This cannot represent the total number of dimes because the expression is in terms of money, not quantity. Similarly, it cannot represent the total value or number of quarters because the value assigned to x in the expression V = 0.25x + 0.10y is 0.25, which is the value of each quarter. Therefore, the expression 0.10y corresponds to the value of the dimes, making option 3 the correct choice.