In mid-May, the depth of a river in Moreland is measured. By mid-June, the river is 10 feet deeper than mid-May. By mid-July, the river is three times deeper than mid-June. If the river is 45 feet deep in mid-July, how many feet deep was the river in mid-May? Give me reasons, before answering the question
In mid - June, the river is 45 / 3 = 15 feet deep. In mid - May, the river was 15 - 10 = 5 feet deep. So the final answer is 5.