If it's a normal rectangular swimming pool then its Area = length x width. So 375 = 25 x width. Divide 25 on both sides. 375/25 = 15, so your width would be 15m.
...Dont get thrown off by the square meters in the area. Area is always measured in sq feet, sq meters, sq yard or sq whatever. The height, length, width or whatever side you are measuring will be normal, in our case meters.
The first step you take is to note that the answer is in meters squared and that the dimensions are meters. Remember that meters x meters will give you meters squared as the answer. So, the missing part is in meters.Then simply divide 375 by 25. The answer is 15. It's a simple division problem with meters as your answer. So labeled correctly, your correct answer is "15 meters".