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?

Respuesta :

Given:
3 bushes for every 1 tree planted
cost of a tree = 75
cost of a bush = 20

75t + 20(3t) = 810
75t + 60t = 810
135t = 810
t = 810 / 135
t = 6

6 trees planted. 

1:3 = 6:x
x = 3*6
x = 18

18 bushes planted.