Answer:
A is right I believe
Step-by-step explanation:
a: 5x
b: 2x
c: 1/5x
d: 1/2x
Let red marbles = X.
The probability is 1 out of 5, written as 1/5
1/5 in terms of red marbles is equal to the number of red marbles divided by 5x, where 5x is the total number of marbles.
1/5 = x/5x
Now you have 5x total marbles, x red and 4x blue.
Add 5 more red and the new probability is:
(x+5)/(5x+5) = 1/3
Simplify:
3x+15 = 5x+5
Now solve for x:
Subtract 3x from both sides:
15 = 2x +5
Subtract 5 from each side:
2x = 10
Divide both sides by 2:
x = 10/2
X = 5
There were originally 5 red marbles.
84 is 60% of 140!
To get this answer, you have to do 84 x 100 and you get 8400: Then you divide 8400 by 60 and get 140.
The answer is B, 20 balls in 4 seconds. Or 5 balls per second.
