Roses can be purchased individually for $2.30, one dozen for $36, or two dozen for $50. What is the greatest number of roses that can be purchased for $680? Choose the correct choice from the following:  A) 156  B) 162  C) 325  D) 324  E) 326

Rationale: "buy as many $ 50 deals as possible . we can by 650 / 50 = 13 two dozen roses , thus total of 13 * 24 = 312 roses . we are left with 680 - 650 = $ 30 . we can buy 30 / 2.3 = ~ 13 roses for that amount . total = 312 + 13 = 325 . answer : c ."
Answer: C