Answer:
Let b = rate of the boat.
Let r = rate of the river.
The rate going downstream is b + r.
The rate going upstream is b - r.
rate x time = distance
4(b + r) = 144 ---> b + r = 36 [divide both sides by 4]
9(b - r) = 144 ---> b - r = 16 [divide both sides by 9]
Add town: 2b = 52
Divide by : b = 26 mi/hr
r = 10 mi/hr
Step-by-step explanation:
Answer:
Letters can be chosen in 12 different ways, if order matters, or 6 different ways, if order doesn't matter.
Step-by-step explanation:
Since we want to choose 2 letters, without replacement, from the 4 letters A, B, C, and D, to determine in how many ways can this be done, if the order of the choices matters, and in how many ways can this be done, if the order of the choices does not matter, the following calculations must be performed:
If order matters =
(4 x 3 x 2 x 1) / 2 = X
24/2 = X
12 = X
If the order doesn't matter =
12/2 = X
6 = X
Therefore, letters can be chosen in 12 different ways, if order matters, or 6 different ways, if order doesn't matter.
Answer:
Step-by-step explanation:
Use proportions to solve.
Corresponding sides have same ratio.
<u>Question 1</u>
- (6x + 3)/17 = (8x - 1)/21
- 21(6x + 3) = 17(8x - 1)
- 126x + 63 = 136x - 17
- 10x = 80
- x = 8
<u>Question 2</u>
- (x + 8)/21 = 32/28
- x + 8 = 21*8/7
- x + 8 = 24
- x = 24 - 8
- x = 16
