00:53:28
Mrs. Grijalva hired a landscaping company to landscape her back yard. The company has a standing policy to plant 3 bushes for every tree planted. The company charges $75 for each tree planted and $20 for each bush. Mrs. Grijalva was billed for $810 after the planting was complete. How many bushes did the company plant in Mrs. Grijalva’s back yard?
A.
2
B.
6
C.
18
D.
54

Question

00:53:28
Mrs. Grijalva hired a landscaping company to landscape her back yard. The company has a standing policy to plant 3 bushes for every tree planted. The company charges $75 for each tree planted and $20 for each bush. Mrs. Grijalva was billed for $810 after the planting was complete. How many bushes did the company plant in Mrs. Grijalva’s back yard?
A.
2
B.
6
C.
18
D.
54

anonymous · Answer

We get 3x as many bushes as trees.
B=3T
Bushes cost $20 each, and trees costs $75 each
Cost=$20∗B+$75∗T
Total cost was $810
810=20B+75T
Now solve by substitution, writing 3T wherever we see B in the cost equation:
810=20(3T)+75T
810=135T
T=6
Plug into formula giving # of bushes for number of trees
B=3T=3(6)=18

anonymous · Answer

Hope I helped