It is 2.5 times more expensive.
50 Percent of 4 is 2.
So, 4 + 4 + 2 = 10
Answer: 54.29%
Step-by-step explanation:
Given: The probability that they will win both games is 38%.
i.e. P( both games will win) =0.38
The probability that they will win just the first game is 70%.
P(first game will win) = 0.70
To find : P(second game will win| first game will win)
Using formula: 
So, P(second game will win| first game will win) = 

Hence, the required probability = 54.29%
Solution:
The given equation is:

A: Taking , x=1
L H S = 9 × 1 + 49 = 9 + 49= 58
R H S : 
L H S ≠ R H S
B: Taking x=3
L H S = 9 × 3 + 49=27 + 49=76
R HS = 
L H S ≠ R H S
C: Taking x=5
L H S = 9 × 5 + 49
= 45 + 49
= 94
R H S:

L H S ≠ R H S
(D)
when , x= 8
L H S
9 × 8 + 49
= 72 + 49
= 121
R HS:

L H S ≠ R H S
The answer is b.18 because there are a total of 630 teachers needed and 630-612=18