Answer:
7/145
Step-by-step explanation:
We have
9 chocolate chip cookies
7 peanut butter cookies
7 sugar cookies
7 oatmeal raisin cookies.
9+7+7+7 = 30 cookies.
What is the probability that Krystal randomly selects a peanut butter cookie from the bag, eats it, then randomly selects another peanut butter cookie?
Initially, there are 30 cookies, 7 of which are peanut butter cookies. So the probability that Krystal selects a peanut butter from the bag is 7/30.
Suppose she selected the peanut butter cookie. Now there are 29 cookies, of which 6 are peanut butter. So the probability that the second one is a peanut butter cookie is 6/29.
Probability that both are peanut butter cookies:
Multiplication

Answer:
2%
Step-by-step explanation:
20% takes 10 years to decay
To find per year decay, we divide the percentage by the number of years, so we get unit rate of years {per year]. Thus we have:
20%/10 = 2% per year
It's that simple.
Hence, the percentage by which the substance decays each year is 2%
Answer:
1. 135°
2. 62°
3. 148°
4. 180-x
Step-by-step explanation:
Supplementary angles are two angles that add to 180 degrees (a straight line).
Therefore, subtract the angle measure they give you from 180.
Hope this helps!
Answer:
Distance between the points Q and R is 1 unit while the distance between the points R and S is 3 units
Step-by-step explanation:
Here, we want to use the absolute value of the coordinates to find the distances.
Since we are using absolute values, the negative points becomes positive;
Thus;
Q = (4,2)
R = (3,2)
S = (3,5)
Mathematically, the distance between two points in the Cartesian plane can be calculated using the formula;
D = √(x2-x1)^2 + (y2-y1)^2
The distance QR is thus;
D = √(3-4)^2 + (2-2)^2
D = √(-1)^2 + 0
D = √1 = 1 unit
The distance RS is thus;
D = √(3-3)^2 + (5-2)^2
D = √(0) + (9)
D = √9 = 3 units