In a workout devoted to JS Core the task to the insight "Get a random item from an Array" contains an error. The situation in the task is absolutely equal to the explanation. Math.random returns a random number between 0 (inclusive) and 1 (exclusive). Multiplying by the length of the array we get the interval [0, 3). Using Math.floor we found a number downward to its nearest integer, so we can get 0, 1, 2. It's fine. The app indicates choosing Math.floor incorrect and accepts Math.ceil. But it rounds a number upward to its nearest integer, sowe can get out of the required interval. E.g.: the result of Math.ceil(2.37..) will be 3, but there is no any element with such an index in the given array. I think it's an error in the app. The answer should be "floor".