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.
Answer:
76 words per minute
Step-by-step explanation:
2964/39=76 words per minute
Answer:
f(t) = 66·0.995^t
Step-by-step explanation:
You can try t=0 and t=1 in each of the formulas to see which one gives values of 66 and 0.5% less than 66, or 65.67.
The first function has an initial value of 0.5, so is not correct.
The second function gives f(1) = 99, so is not correct.
The third function gives f(1) = 65.67, so is correct.
The fourth function gives f(1) = 66.33, so is not correct.
_____
You can realize that the multiplier will be 0.5% less than 100%, so will be 99.5% = 0.995. This number shows up only in the third selection.
Answer:
C) 17
Step-by-step explanation:
Using the rule
A^2 + B^2 = C^2
8^2 + 15^2 = x^2
64 + 225 = x^2
x^2 = 289
x= _/-289
x = 17