Step-by-step explanation:
Let's say b is the rate of the boat in still water, and c is the rate of the current.
Distance = rate × time
Going upstream:
100 = (b − c) (5)
20 = b − c
Going downstream:
100 = (b + c) (2)
50 = b + c
Solve the system of equations using substitution or elimination. Using elimination, add the equations together:
70 = 2b
b = 35
c = 15
The boat's speed is 35 km/h, and the current's speed is 15 km/h.
-6 is greater than 5 is wrong
D
10^-3 would make a decimal, so would 10^-1.
10^1 would be 30 miles, 10^3 would be 3 with 3 zeros ( 3000 miles) which would be most accurate