Fifth National bank offers four different certificates of deposit (CD). The first CD (A) offers a 4% interest rate for amount greater than $10,000. The second CD (B) offers a 4.2% interest rate for amount greater than $25,000. The third CD (C) offers a 4.5% interest rate for amount greater than $30,000. Finally, the fourth CD (D) offers a 5% interest rate for amount greater than $35,000. A customer has $150,000 to deposit. She wishes to deposit not more than 1/3 of her money in any of the CDs. She likes to deposit exactly three times of her money in CD#2 than CD#1. She wishes the sum of the first and the second CDs to be less than or equal to the third CD.
Question 2
What is the “deposit exactly three times of her money in CD#2 than CD#1” constraint equation?

3A * B

A = 3B

B − 3A = 0

A − 3B = 0