A Mixture of 7 Pounds of Fertilizer A,21 Pounds of Fertilizer

Multiple Choice

A mixture of 7 pounds of fertilizer A,21 pounds of fertilizer B,and 8 pounds of fertilizer C provides the optimal nutrients for a plant.Commercial brand X contains equal parts of fertilizer B and fertilizer C.Commercial brand Y contains one part of fertilizer A and two parts of fertilizer B.Commercial brand Z contains two parts of fertilizer A,five parts of fertilizer B,and two parts of fertilizer C.How much of each fertilizer brand is needed to obtain the desired mixture? ​

A) Brand X = 12 lb Brand Y = 15 lb
Brand Z = 9 lb
B) Brand X = 12 lb Brand Y = 9 lb
Brand Z = 9 lb
C) Brand X = 12 lb Brand Y = 15 lb
Brand Z = 15 lb
D) Brand X = 12 lb Brand Y = 9 lb
Brand Z = 15 lb
E) Brand X = 9 lb Brand Y = 15 lb
Brand Z = 12 lb