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

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

texaschic101 · Answer

t = tree
b = bushes

75t + 20b = 810
t = 3b
This is not correct, because when I work this out, it does not come out right ??
I am trying to figure out another way to do this.

texaschic101 · Answer

@goformit100 ....can you help

texaschic101 · Answer

@moongazer ...can you look at this please

texaschic101 · Answer

@UnkleRhaukus ...can you take a peek at this

texaschic101 · Answer

@bahrom7893 ....help

texaschic101 · Answer

@whpalmer4 ...can you help me set this up

anonymous · Answer

i ALREADY GOT IT

texaschic101 · Answer

how did you set it up ?

anonymous · Answer

I didnt mines a credit recovery online assignment so i dont have to show work or setit up i just guessed and got it right

texaschic101 · Answer

oh.....whatever works

anonymous · Answer

yea but thanks

whpalmer4 · Answer

Okay, we can probably eliminate A as a possible answer choice immediately, because it is not a multiple of 3, and we're told they always plant 3 bushes for every tree.  I suppose it is possible that on a small enough job they might not plant any trees, but that job shouldn't cost $810, either.  Whatever.  A is not the 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$$B=3T = 3(6) = 18$$

whpalmer4 · Answer

@texaschic101 we both made the same mistake, setting up the bush/tree relationship backward :)

whpalmer4 · Answer

Another way to look at this:  A tree + 3 bushes is the basic unit that they sell, and costs $75+3*$20 = $135.  How many of those units do you get for $810?

texaschic101 · Answer

oh.....I see now.....this problem was bugging me.....even if the asker didn't want to know how to do it, I couldn't get the problem out of my mind. Thanks for explaining it to me. I get it now.

anonymous · Answer

whats the answer

whpalmer4 · Answer

@asmccash if you read my posts carefully, you'll find the answer.

anonymous · Answer

whats the answer i need to know plz