The amount of rainfall in July was 6.1 inches.
Work Step by Step
Let X represent the amount of rainfall in inches in July. The rainfall in June was 11.2 inches. This was 1 inch less than twice the rainfall in July. Twice the rainfall in July means 2X. 1 inch less than twice the rainfall in July means 2X - 1. Thus, we obtain: 11.2 = 2X - 1 Add 1 to both sides: 12.2 = 2X Divide both sides by 2 6.1 = X