maths
posted by roger on .
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

since distance = speed*time, if the stillwater speeds of the men are a and b,
(a.5)(5) = 10
(b+.5)(3) = 10
5a  5/2 = 10
3b + 3/2 = 10
ba = (10  3/2)/3  (10+5/2)/5 = 1/3 
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 
1.33

upstream speed =Distance/time
=10/5=2 kmph
downstream speed of =10/3=3.33kmph
difference =3.332=1.33