Hi, I know this is simple but I'd like someone to clarify for me, because my lecturer wasn't clear: Obviously when the pipes are in parallel, the head losses across them are the same. But what about the total head loss for the parallel pipes as a whole? I have 3 ideas, but I'm not sure which would be correct: 1) Treating the head losses the same way as electrical resistance, where 1/R=1/R1 + 1/R2... but with head losses instead of resistance? 2) Simply adding them up? 3) The total head loss across all the parallel pipes is equal to that across just one of the individual pipes? I feel like it's the third option, but I'm not entirely sure. Can you tell me which is correct (if any), and explain why please. Thanks.