# Pratap Puri rowed 18 miles down the Delaware River in 2 hours, but the return trip took him 42 hours. How do you find the rate Pratap can row in still water and find the rate of the current?

Oct 18, 2016

$\frac{33}{7} m p h \mathmr{and} \frac{30}{7} m p h$

#### Explanation:

Let Puri's rowing speed be ${v}_{P}$ mph. Let the speed of the current

be ${v}_{C}$ mph.Then, for the down stream rowing,

Resultant ( effective )

speed X time = 2(v+P+v_C)= distance = 18 miles.

For the up stream rowing,

#42 ( v_P-v_C)= 18 miles.

Solving,

${v}_{P} = \frac{33}{7} m p h \mathmr{and} v + C = \frac{30}{7} m p h$

.