Answer:
17/300.
Step-by-step explanation:
17/300 students have a dog.
Answer: There are 20 ways and 1680 ways respectively.
Step-by-step explanation:
Since we have given that
Total number of blocks = 6
Number of red blocks = 3
Number of green blocks = 3
So, Number of patterns she can make by placing them all in a line is given by

If there are 3 white blocks
so, total number of white blocks becomes 9
So, Number of total pattern she can make by placing all nine blocks in a line is given by

Hence, there are 20 ways and 1680 ways respectively.
Answer: 1- a square has 4 equal sides so if one side is 9cm then the rest are 9cm, so 9x4= 36cm
2- do the same thing as part 1 but add a power of 2 to it, so 36^2 = 1296cm
Step-by-step explanation:
Answer:
1. 6/7
2. 1/2
3. 7/10
4. 39/40
5. 15/28
6. 3/10
7. 7/12
8. 1/6
9. 5/12
10. 1/8
Step-by-step explanation:
Answer:
Step-by-step explanation:
1) Let the random time variable, X = 45min; mean, ∪ = 30min; standard deviation, α = 15min
By comparing P(0 ≤ Z ≤ 30)
P(Z ≤ X - ∪/α) = P(Z ≤ 45 - 30/15) = P( Z ≤ 1)
Using Table
P(0 ≤ Z ≤ 1) = 0.3413
P(Z > 1) = (0.5 - 0.3413) = 0.1537
∴ P(Z > 45) = 0.1537
2) By compering (0 ≤ Z ≤ 15) ( that is 4:15pm)
P(Z ≤ 15 - 30/15) = P(Z ≤ -1)
Using Table
P(-1 ≤ Z ≤ 0) = 0.3413
P(Z < 1) = (0.5 - 0.3413) = 0.1587
∴ P(Z < 15) = 0.1587
3) By comparing P(0 ≤ Z ≤ 60) (that is for 5:00pm)
P(Z ≤ 60 - 30/15) = P(Z ≤ 2)
Using Table
P(0 ≤ Z ≤ 1) = 0.4772
P(Z > 1) = (0.5 - 0.4772) = 0.0228
∴ P(Z > 60) = 0.0228