Let x be the rate of the slower bicyclist and
x + 4 be the rate of the faster bicyclist
Since the bicyclists are headed towards opposite directions, the sum of the distances they covered traveling for one hour and 15 minutes should be equal to 40 km based on the given conditions above. This may be expressed as,
(x)(1.25) + (x + 4)(1.25) = 40
Calculating gives x = 14
Thus, the rate of the bicyclists are 14 km/h and 18 km/h.
317 is the answer you are looking for.
Answer:
Time taken by the un powered raft to cover this distance is T = 192.12 hr
Step-by-step explanation:
Let speed of boat = u 
Speed of current = v 
Let distance between A & B = 100 km
Time taken in downstream = 32 hours


u + v = 3.125 ------ (1)
Time taken in upstream = 48 hours


u - v = 2.084 ------- (2)
By solving equation (1) & (2)
u = 2.6045 
v = 0.5205 
Now the time taken by the un powered raft to cover this distance

Because un powered raft travel with the speed of the current.

T = 192.12 hr
Therefore the time taken by the un powered raft to cover this distance is
T = 192.12 hr
14.75x - 23=5.25x+45.2
14.75x-23-5.25x=5.25x+45.2-5.25x
14.75-5.25x=9.5
9.5x-23=45.2
9.5x-23+23=45.2+23
9.5x=68.2
9.5x/9.5=68.2/9.5
x=7.178947