Question

18. (1) Given, rate of stream ( =1.5 mathrm{km} / mathrm{h} ) We know that, rate of stream ( =frac{1}{2} ) (speed
downstream - speed upstream) ( Rightarrow quad 1.5=frac{1}{2} )
( (11-text { speed upstream }) )
( Rightarrow quad 11- ) speed upstream ( =3 )
( therefore quad ) Speed upstream ( =8 mathrm{km} / mathrm{h} )

# 18. A swimmer's speed downstream is 11 km/h and speed of the stream is 1.5 km/h. Find the upstream speed of swimmer. (1) 8 km/h (2) 9.5 km/h (3) 9 km/h (4) 6.25 km/h

Solution