Tolong dong no. 3 nyaa ^^

a. kalau parallel, konstantanya ditambah aja
400 + 400 + 400 + 400 = 1600

b. kalau seri, konstantanya 1/ k1 + 1/k2 + 1/kn
1/400 + 1/400 + 1/400 + 1/400 = 4/400 = 1/100

k = 100

kalau yang c, (1/300) x 4 = 4/300... 1
(1/300) x 2 = 2/300......2
300......3

4/300 + 2/300 + 300 = 350