P = U * I = U * U / R ,R = U * U / P :
R40 = 110 * 110 / 40 = 302.5 Ω
R25 = 484 Ω
I = 110 / (302.5 + 484 ) ≈ 0.14 A
P = U * I = I * I * R :
P40 = 0.14 * 0.14 * 302.5 ≈ 5.92 W
P20 ≈ 9.47 W厉害！