There are 10 chips altogether. 4 of them are white.
4/10 is the chance of lifting out a white chip
There are 3 of them left and 9 chips altogehter.
4/10 * 3/9
12/90
4/30
2/15
Comment
(my edit) it is not that 2/15 is wrong (although it is not entirely right).
1/3 is the correct answer if you assume that what happened during the first draw has nothing to do with what will happen on the second. It is like saying if you throw 11 heads in a row with a fair coin, what are the chances of throwing a heads on the 12th throw? The answer is 1/2. That is the same kind of question you have asked.
The two of us who have responded have really responded to what are the chances of drawing 2 white chips. The question really does not restrict us in a way that prevents us from saying that. I'll stick with
B <<<< answer
but I think it would be nice if the writer of the question made it clear that 1/3 should be the proper answer. I am glad you came back and posted the right answer. It makes me think.
The semi right answer is B <<<<----
If my reasoning bothers anybody, I'll reedit again. I'm only leaving it because sometimes a mistake is more instructive than a given answer.
Answer:
Train A = 128
Train B = 68
Step-by-step explanation:
We can set up a system of equations for this problem
Let A = # of tons of Train A
Let B = # of tons of Train B
A + B = 196
A = B + 60
Now, we plug in A for the first equation, using substitution
(B+60) + B = 196
2B + 60 = 196
Subtract 60 from both sides
2B = 136
Divide both sides by 2
B = 68
Plug in 68 for B in the 2nd equation
A = 68 + 60
A = 128
Checking work: 128 + 68 = 196 :D hope this helped
Answer:
it will take 1.4 hours for the two trains to be 294 miles apart
Step-by-step explanation:
Let t be the time taken for each train
The westbound train travels at 95 miles per hour.
Speed of westbound train = 95
time = t
Distance = speed * time = 95 t
The eastbound train travels at 115 miles per hour
Speed of eastbound train = 115
time = t
Distance = speed * time = 115 t
both trains are 294 miles apart means the distance between both trains are 294 miles
So we add the distance of both trains and set it equal to 294
95t + 115t = 294
210 t =294
t = 1.4
So, it will take 1.4 hours for the two trains to be 294 miles apart
Answer:
4 x^3 - 3 x^2
Step-by-step explanation:
Expand the following:
x^2 (4 x - 3)
x^2 (4 x - 3) = x^2×4 x + x^2 (-3):
4 x^2 x - 3 x^2
x^2×4 x = x^(2 + 1)×4:
4 x^(2 + 1) - 3 x^2
2 + 1 = 3:
Answer: 4 x^3 - 3 x^2
Solution: The speed of old freight train is 0.5 miles per minute and the speed of new dart express train is 1.5 miles per minute.
Explanation:
Let the speed of old freight train is x miles per minute and the speed of new dart express train is y miles per minute.
It is given that the speed of the dart express train is three times faster than the freight train. So, it can be written as,
....(1)
The trains are moving towards the opposite directions, therefore the distance between them is increased at the speed of 
miles per minute.
The distance between both train in 15 minutes is represented by 
.
According to the given information the distance between trains is 30 miles in 15 minutes.
Use equation (1) and put 
Put this value in equation (1), to find the value of y.
Therefore, the The speed of old freight train is 0.5 miles per minute and the speed of new dart express train is 1.5 miles per minute.
