## Question

**A boy can swim in still water at 4.5 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is ?**

A. 1.5 kmph

B. 1.8 kmph

C. 2 kmph

D. 2.2 kmph

#### Answer: A. 1.5 kmph

**Solution:**

Speed of Boy is B = 4.5 kmph

Let the speed of the stream is S = x kmph

Then speed in Down Stream = 4.5 + x

speed in Up Stream = 4.5 – x

As the distance is same,

=> 4.5 + x = (4.5 – x) 2

=> 4.5 + x = 9 -2x

3x = 4.5

**x = 1.5 kmph**

Hence, The Answer is **1.5 kmph.**

**Read more:**

**If the cost price of 12 pens is equal to the selling price of 8 pens, the gain percent is ?**