A boat travels 52 miles upstream in the same amount of time that it travels down stream 85 miles. If the stream is moving at a rate of 4 mph find the rate of the boat in Still water

2.44706 mph

Step-by-step explanation:

Given that :

Distance = rate * time

Rate of boat + rate of current = 4mph

If rate of current = c ;

Downstream:

85 = 4t

Upstream :

52 = (4 - c)t

85/4 = 52/(4 - c)

85(4 - c) = 52 * 4

340 - 85c = 208

-85c = - 132

c = 132 / 85

c = 1.55294

Rate of boat in still water :

4 - c

4 - 1.55294

= 2.44706 mph

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)