Answer:
The rate of the current is 2 miles per hour.
Step-by-step explanation:
Let us assume that the rate of the river is v miles per hour.
The speed of the boat is 12 miles per hour.
Let us assume also that the boat can go 21 miles in t hours in the downstream and 15 miles upstream at the same time i.e. t hours.
So, from the condition given we can write that
......... (1), and
......... (2)
Now, adding those two equations we get
⇒ 
hours
Now, from equation (1), we get,
⇒ v = 2 miles per hour
Therefore, the rate of the current is 2 miles per hour. (Answer)
The number of possible combinations is given by
... C(18, 3) = 18!/(3!(18-3)!) = 18·17·16/(3·2·1) = 816 . . . . possible combinations
_____
There are 18 ways to choose the first one; 17 ways to choose the second one, and 16 ways to choose the 3rd one. The same 3 students can be chosen in any of 3! = 6 different orders, so the product 18·17·16 must be divided by 6 to get the number of possible combinations in which order doesn't matter.
Answer:
-7/5
Step-by-step explanation:
The slope of a perpendicular line is the "negative reciprocal" of the slope of the original line. so just switch the numbers and put the top number into a negative.
Answer:
The answer to your question is x = 21
Step-by-step explanation:
Equation
- Multiply both sides by 7
- Simplify
2x = 42
- Divide both sides by 2
- Simplify
x = 21
Answer:
A
Step-by-step explanation:
950 is 95% of 1000
so he lost 5 percent, which can be represented as -5.0%
