Pacemakers which are designed for long-term use commonly employ a lithium-iodine battery capable of supplying 0.42 A x h of charge. (a) How many coloumbs of charge can such a battery supply? (b) If the average current produced by the pacemaker is 5.6 mcA, what is the expected lifetime of the device? I am pretty sure I have to use the equation I = Q/t, so Q = It? How do I get t, since it is not mentioned at all? Does this have anything to do with the "x h" mentioned in the problem?