#### Answer

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