Answer:
The answer is option 3.
Step-by-step explanation:
You have to substitute H+=2×10^(-9) into the equation of pH :
pH = -log[H+]
H+ = 2×10^(-9)
pH = -log[2×10^-9]
= 8.70 (3s.f)
Four because 90+90+90+90 = 360, which is the angle f a circle
Let us consider the number of edges = x
we know that a triangle will have 3 edges and a square will have 4 edges. Using this details we can form an equation.
3x + 4x = 8484
7x = 8484
x = 8484/7
= 1212
Then
Number of square tiles = 1212/4
= 303
So there are 303 square tiles in the box. I hope the procedure is clear enough for your understanding. You can always use this method for solving similar problems.
Answer: a) 0.8413, b) 0.9987.
Step-by-step explanation:
Since we have given that
Mean = 3 pounds
Standard deviation = 0.25 pounds
n = 28 bricks
So, (a) What is the probability that all the bricks in the sample exceed 2.75 pounds?
b) What is the probability that the heaviest brick in the sample exceeds 3.75 pounds?
Hence, a) 0.8413, b) 0.9987.
2x2x2 = 8
4 x 2 x 2 = 16
16+8 = 24
Answer is A
