Question

A man goes upstream for a distance of 10 kms in 5 hours. Another man goes downstream the same distance of 10 kms in 3 hours. what is the difference in speeds of two men if the river speed is 0.5 km/hr

Answer 1

since distance = speed*time, if the still-water speeds of the men are a and b,

(a-.5)(5) = 10
(b+.5)(3) = 10

5a - 5/2 = 10
3b + 3/2 = 10

b-a = (10 - 3/2)/3 - (10+5/2)/5 = 1/3

Answer 2

Sir, I am also getting this as the answer. but the options given are :-

a). 2.45
b). 2.3
c). 1.33
d). 1.56

Answer 3

1.33

Answer 4

upstream speed =Distance/time
=10/5=2 kmph
downstream speed of =10/3=3.33kmph
difference =3.33-2=1.33