NB: Algebra question. As Carlos swims the lowest amount of lengths compared to Raf and Freya, and the information from the question follows from the total amount Carlos has swam, we use the symbol 'S' to denote the amount of lengths Carlos has swam. From here it can be deduced that '4*S' is the amount of lengths Jasmin has swam and '4S + 30' is the amount of lengths Raf has swam. The sum of these four 'S + 4S + (4S + 30) = 372. By simplification and rearrangement we get:9S = 372 - 30 ------------> 9S = 342 --------------> S = 38.Carlos swims a total of 38 lengths, Jasmin 152 and Raf 182.