If Keaton climbed his ladder twenty times, he covered a length of 30*20 = <<30*20=600>>600 feet.
Reece's ladder, 4 feet shorter than Keaton's ladder, was 30-4 = <<30-4=26>>26 feet long.
If Reece climbed the ladder 15 times, he covered a length of 15*26 = <<15*26=390>>390 feet.
Keaton and Reece's total length covered while climbing the ladders is 390+600 = <<390+600=990>>990 feet.
Since one foot is equal to 12 inches, the total length they climbed the ladders in inches is 12*990 = <<12*990=11880>>11880 inches.
#### 11880