We are given with an initial deposit of $20,000 and a future worth of <span>$35,000. In this case, we are asked for the return of income (ROI) of the investment. in this case, we assume the number of years equal to 1. hence,
</span>$35,000 = <span>$20,000* (1+i) ^1
</span>i or ROI then is equal to 0.75
We have been given that the upstream speed is
and the down stream speed is
.
Let the fisherman traveled a distance of x miles.
The total time of the trip is 6 hours.
Relations between speed (s), time (t) and distance (d) is 
Hence, 
Time upstream + time downstream = 6

lcm = 10

=> 
Cross multiplying, 
x = 20 miles .. Answer.
-1, 0.5, 2/3, 1.1 is the order of the numbers from least to greatest
Principal = 109,000
Return - 9,920
Return = (principal x rate x time)/100
X = the amount invested at 12%
Then 102000- x = the amount invested at 8%
9920 = (x*12)/100 + (109000-x*8)100
x = 30,000
a) 30,000 is invested at 12%
79,000 is invested at 8%
b) The 12% investment is riskier so if all the money was in that account the investor could lose all his money.