there are 3600 seconds per hour
5280 feet per mile
1 foot per second = 3600/5280 = 0.681818 Miles per Hour
60 seconds per minute
so 1500/60 = 25 feet per second
25 x 0.681818 = 17.05 miles per hour
5:8 and 20:32 would be a proportion.
Easy way to find this:
Set up the proportion as a fraction.
Use the cross product property. Multiply the diagonals and if the products of the diagonals are the same, then they are proportional.
For
1. its
D=Days
H=Hours
M=Minutes
3d+5h+15m
3d=72h+5h
72h+5h=77h
77h+15m=77h.15m
But i only have this one right now sorry :P