Question

Speed of boat in upstream is 3/4 that of downstream . find the ratio of speed of boat in still water and to the average speed of boat in downstream and upstream.

Answer 1

Answer: The ratio of  speed of boat in still water and to the average speed of boat in downstream and upstream is 1:1.

Step-by-step explanation:

Since we have given that

Let the downstream  speed of boat be x

Let the upstream speed of boat be

$\frac{3}{4}x$

Average speed of boat in downstream and upstream is given by

$\frac{x+\frac{3}{4}x}{2}\\\\=\frac{7x}{8}\\\\=\frac{7}{8}$

Speed of boat in still water is given by

$\text[Speed of boat in still water }=\frac{Downstream+Upstream}{2}=\frac{x+\frac{3}{4}x}{2}\\\\=\frac{7x}{8}\\\\=\frac{7}{8}\frac{7}{8}$

Hence, the ratio of  speed of boat in still water and to the average speed of boat in downstream and upstream is 1:1.