Question

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

11th - 12th Class

Maths

Solution

4.0 (1 ratings)

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} )