Answer:
The probability is 
Step-by-step explanation:
From the question we are told that
The number of green marbles is 
The number of red marbles is 
The number of red marbles is 
Generally the total number of marbles is mathematically represented as



Generally total number of marbles that are not red is

=> 
=> 
The probability of the first ball not being red is mathematically represented as

=> 
The probability of the second ball not being red is mathematically represented as

=>
(the subtraction is because the marbles where selected without replacement )
=> 
The probability that the first two balls is not red is mathematically represented as

=>
=>
The probability of the third ball being red is mathematically represented as
(the subtraction is because the marbles where selected without replacement )

=> 
Generally the probability of the first two marble not being red and the third marble being red is mathematically represented as


=> 
Numerator 6x - 18 = 6(x - 3)
Denominator x^2 - 5x + 6 = (x - 3)( x - 2)
If you are given with all the tree sides of the triangle, you may solve for all the angles through the Law of Cosines,
c² = a² + b² - 2ab(cos C)
where angle C is the angle opposite the side c. You may use the same equation to get the values of the remaining angle. Additionally, if you already have one known angle, you can solve for the rest of the angles by Law of Sines,
a / sin A = b / sin B = c / sin C
3600 boxes divided by 60 trucks = 60 boxes per truck.