Answer: 8
Step-by-step explanation:
Given: A bag contains three red marbles, two green ones, one lavender one, two yellows, and two orange marbles.
Total marbles other than green = 8
Total marbles other than green and yellow = 6
Then the number of sets of seven marbles include at least one yellow one but no green ones:-

Number of sets of seven marbles include at least one yellow one but no green ones = 8
So the book guy mark downed the price of the books by 46%, also known as 0.46. All decimals are less than 1. So then, what you do is you take b, which is the variable defining the price of the book, then you multiply it by 0.46. So the answer of b would be b x 0.46. For C, you must do 29 x 0.54, and that will give you the answer for C. Finally, in D, take the answer you got in C, and subtract that by 29. This will give you your answer.