R C2 9 What are the (a) size and (b) direction (up or down) of current i in Fig. 27-20, where all resistances are 4.0 22 and all batteries are ideal and have an emf of 10 V? (Hint: This can be answered using only mental calculation.) 18 R3 w Figure 27-19 Problem 8. 1 w } w HH + 16 w w Figure 27-20 Problem 9.