Se
5a and
has
4. it takes 21 hours for 12 men to resurface a
stretch of road. find how many men it takes to
resurface a similar stretch of road in 50 hours
24 minutes, assuming the work rate remains
constant.
[5]
5. it takes 3 hours 15 minutes to fly from city a
to city b at a constant speed. find how long
the journey takes if
(a) the speed is 1 times that of the original
speed and
(b) if the speed is three-quarters of the orig-
inal speed.
[(a) 2 h 10 min (b) 4h 20 min)
to 1) or