R=rate of boat in still water
c=rate of current
d=rt
since you're given that the time it takes to travel the same distance downstream and upstream, your equation will be d_1=d_2, or rt=rt
the rate upstream is r-c and the rate downstream is r+c (because the boat's and river's rates add up)
since you know t_1 and t_1 are 5 and 3, you can now set up 2 equations
<u>5*(r-c)=45</u> because (time upstream)*(rate upstream)=distance=45 miles
r-c=45/5=9
<u>3*(r+c)=45</u>
r+c=45/3=15
r-c=9 and r+c=15, so r=12 mi/h and c=3 mi/h
If you have any questions please ask
1% = 1/100
1600 x 1/100 = 1600/100
16
A + b +c = 75; where a is the greatest number; b is the middle number; c is the least number;
a = 2 * c;
b = 3 + c;
then, 2 * c + 3 + c + c = 75 => 4 * c = 72 => c = 72 / 4 => c = 18 => a = 2 * 18 => a = 36; b = 3 + 18 => b = 21;
Floats withdrew 630 dollars from her bank account