The co$t of soccer balls
A box contains 11 soccer balls.
Three cost 40$ each, four cost 80$ each and another 4 cost 150$ each.
Three soccer balls are randomly chosen from the box without replacement.
What is the probability that the total cost of the three balls is 300$ or more?
The probability can be expressed as a/b for co-prime positive integers a and b, find the value of a+b.