Dont ask me why...I cant really explain it...but if u have 1 repeating decimal, u put it over 9. If u have 2 repeating decimals, u put it over 99....3 repeating decimals, put it over 999.
Examples :
0.7 (repeating) = 7/9
0.27 (repeating) = 27/99 when simplified = 3/11 <===
0.444 (repeating = 444/999
Let the boat speed in still water be b.
Let the current speed be c.
The speed going upstream is 20/4 = 5 mph.
The speed going downstream is 32/4 = 8 mph.
b - c = 5 ........(1)
b + c = 8 .......(2)
Adding equations (1) and (2) we get:
2b = 13
b = 13/2 = 6.5
Plugging in the value for b into equation (1) we find c = 1.5.
The boat speed in still water is 6.5 mph and the current speed is 1.5 mph.
Answer: C) 9/41
Step-by-step explanation: From the description, angle S is the right angle. Which means that angles T and R are complementary (they sum to 90 degrees). Because they are complementary, this means the cosine of one angle is equal to the sine of the other angle. If cos(T) is 9/41, then so is sin(R).
cr. USA Test Prep