Answer:
2 mph
Step-by-step explanation:
time = distance / speed
Let c represent the rate of the current. Then the upstream rate of the boat relative to the shore is (5c -c) = 4c, and the <em>upstream time</em> is ...
... 12/(4c) = 3/c.
Likewise, the downstream rate is (5c +c) = 6c, and the <em>downstream time</em> is ...
... 12/(6c) = 2/c.
The <em>total time</em> is the sum of upstream and downstream times:
... 3/c +2/c = 2.5
... 5/c = 2.5 . . . . . . combine terms
... 5/2.5 = c = 2 . . . multiply by c/2.5
Answer:
<em>Assuming person A and person B are part of the 7 people</em>, there are 10 ways the 7 people can line up if A needs to be first or last and B needs to be in the middle.
Step-by-step explanation:
There are 2 places for A (first, last) and 5 places for B (anywhere but first or last). 2 x 5 = 10.
Answer:
3.4028 x 10^-1
Step-by-step explanation:
First you make the 9400 into scientific notation:
9.4x10^3
Then you combine like terms
(3.62x9.4)(10^-5x10^3)
Finally you simplify
34.028x10^-2
3.4028x10^-1
