Question
How much longer does it take an automobile to travel one mile at 20 miles per hour than at 30 miles per hour?
a) 1 minute
b) 10 minutes
c) 20 minutes
d) None of these answers
a) 1 minute
b) 10 minutes
c) 20 minutes
d) None of these answers
Answers
R_scott
20 mph ... 1/20 hr per mile
30 mph ... 1/30 hr per mile
60 minutes in an hour
30 mph ... 1/30 hr per mile
60 minutes in an hour
oobleck
20 mi/hr =1/3 mi/min = 3 min/mi
30 mi/hr = 2 min/mi
so, 1 minute longer
30 mi/hr = 2 min/mi
so, 1 minute longer
henry2,
20mi./60min = 1/3 mi./min. = 3 min./mi.
30mi/60min. = 1/2 mi/min = 2 min/m1.
3-2 = 1 min. longer.
30mi/60min. = 1/2 mi/min = 2 min/m1.
3-2 = 1 min. longer.
Well, 1.02 is pretty close to 1 :)