Bunuel wrote:
Seed X costs $5 per pound and Seed Y costs $7 per pound. Seed Z is a blend of the two seeds, and 20 pounds of Seed Z contains a pounds of Seed X and b pounds of Seed Y. Is a > 10?
(1) 20 pounds of Seed Z costs less than $120
(2) b < 12
Quote:
If Seed Z were made of exactly ½ Seed X and ½ Seed Y, then the cost of Seed Z would be $6 per pound (exactly halfway between $5 and $7). So if 20 pounds of Seed Z costs $120 ($6 per pound) then a = 10 and b = 10. Statement 1 tells you that the total of 20 pounds of Seed Z is LESS than $120 so there must be more pounds of Seed X than Seed Y. This means than a must be greater than 10 and statement 1 is sufficient.
Quote:
Statement 2 if b = 11 then a would be 9 and the answer is no to the question. However if b = 4 then a = 16 and the answer is yes. Statement 2 is not sufficient and the answer is A.