2. Fan-Out Wire

How do you plan to solve it?

assign a to y1, y2 and y2 one by one.

module top_module(
    // Declare Inputs and outputs here
    input a,
    output y1, y2, y3
);
    // Module functionality here
    assign y1 = a;
    assign y2 = a;
    assign y3 = a;

endmodule