Model joint and combined variation equations

Q1. If y varies jointly (directly) as x and w, how will y_1 change
when x_1 is doubled and w_1 is one fourth of its original value?

Q2. If y varies directly as the square root of x and inversely as the square of w, by what factor will y_1 change when x_1 is made
four times larger and w_1 is tripled?