Answer:
B. 0.4
Step-by-step explanation:
Use the definition of the probability

You have to find the probability that a randomly selected reference book is hard cover. Hence, from the table
- Number of all possible outcomes = Number of Reference books = 25
- Number of all favorable outcomes = Number of Hardcover Reference books = 10
So, the probability is

Formula of the Volume of a hemisphere:
V =


r³
144

=


r³
Multiply by 3 to cancel fraction in the right side
144

× 3 = 2

r³
432

= 2

r³
Divide by 2

on either sides to isolate r³

=

r³
2

and

cancel out
216 = r³
Take cube root to find the radius
![\sqrt[3]{216}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B216%7D%20)
=
![\sqrt[3]{r^3}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7Br%5E3%7D%20)
6 = r
Radius is 6 unitsThe formula of the surface area of a hemisphere is:
S.A = 2

r² +

r²
=

(6)² +

(6)²
=2

× 36 + 36

= 72

+ 36

= 108

units² (in terms of

)
≈ 339.12 units²
Surface area = 108
units
<u>Answer:</u>
- 6. 6.75
- 7. 27
- 8. 92/17
- 9. 49
<u>Step-by-step explanation:</u>
<u>- Question 6 -</u>
- 9/16 = x/12
- => 16x = 12 x 9
- => 16x = 108
- => x = 6.75
Hence, <u>the value of x in this proportion is 6.75.</u>
<h3>_______________________________</h3>
<u>- Question 7 -</u>
- -3 + x/18 = 12/9
- => -3/18 + x/18 = 4/3
- => x/18 = 4/3 + 1/6
- => x/18 = 8/6 + 1/6
- => x/18 = 9/6
- => x = 9/6 x 18
- => x = 27
Hence, <u>the value of x is 27</u>
<h3>_______________________________</h3>
<u>- Question 8 -</u>
17/15 = 10/2x - 2
=> 17(2x - 2) = 150
=> 34x - 34 = 150
=> 34x = 184
=> x = 184/34
=> x = 92/17
Hence, <u>the value of x is 92/17</u>
<h3>_______________________________</h3>
<u>- Question 9 -</u>
- x - 16/x + 6 = 3/5
- => 5(x - 16) = 3(x + 6)
- => 5x - 80 = 3x + 18
- => 2x = 98
- => x = 49
Hence, <u>the value of x is 49.</u>
<h3>_______________________________</h3>
Hoped this helped.