1. 6 / 30 = x / 60....6 in to 30 min = x in to 60 min
cross multiply
(30)(x) = (6)(60)
30x = 360
x = 360/30
x = 12 inches in 60 minutes (or 1 hr)
2. 1/15 = x / 30.....1 in to 15 min = x in to 30 min
cross multiply
(15)(x) = (30)(1)
15x = 30
x = 30/15
x = 2 inches in 30 min (or 1/2 hr)
3. 3/20 = x/120....3 in. to 20 min = x in. to 120 min (2 hrs = 120 min.)
cross multiply
(20)(x) = (3)(120)
20x = 360
x = 360/20
x = 18 inches in 120 minutes (or 2 hrs)