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?
In mid-June, the river is 45/3=<<45/3=15>>15 feet deep.
In mid-May, the river was 15-10=<<15-10=5>>5 feet deep.
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