Problem: A box contains chips, each of which is red, white, or blue. The number of blue chips is at least half the number of white chips, and at most one third the number of red chips. The number which are white or blue is at least 55. The minimum number of red chips is
Answer Choices:
A. 24
B. 33
C. 45
D. 54
E. 57
Solution:
Let w,b, and r denote the numbers of white, blue, and red chips respectively. Then w≤2 b and 3 b≤r. Now w+b≥55∴2 b+b=3 b≥55∴ b≥1831​∴19≤ b∴57≤3 b≤r. The minimum number of red chips is 57 .