Chamblee High School is selling Valentine's Day gifts as a fundraising event. One long stemmed rose costs $3.00 while one long stemmed carnation costs $1.50. If 50 orders were placed and they totaled $195, how many roses and carnations were ordered?
100 roses and 100 carnations
60 roses and 10 carnations
125 roses and 75 carnations
50 roses and 145 carnations

 Choice B) 60 roses and 10 carnations

Explanation:

r and c are positive whole numbers.

r+c = total number of flowers = 50, since 50 orders are made.

The first equation to set up is r+c = 50.

This equation can be solved to get r = 50-c.

3r = cost of all the roses only, in dollars

1.5c = cost of all the carnations only, in dollars

3r+1.5c = total cost of all the flowers = 195 dollars

3r+1.5c = 195

Let's apply substitution to solve

3r+1.5c = 195

3(50-c)+1.5c = 195

150-3c+1.5c = 195

-1.5c+150 = 195

-1.5c = 195-150

-1.5c = 45

c = 45/(-1.5)

c = -30

That's not good. We shouldn't get a negative value.

It turns out that the condition r+c = 50 should be ignored. Notice how none of the answer choices listed have r+c leading to 50.

So we'll only focus on the equation 3r+1.5c = 195

If we plugged in r = 100 and c = 100, then we get

3r+1.5c = 195

3(100)+1.5(100) = 195

300+150 = 195

450 = 195

Which is false. So we can rule out choice A

Let's repeat those steps for choice B

3r+1.5c = 195

3(60)+1.5(10) = 195

180 + 15 = 195

195 = 195

So that works out. I have a feeling your teacher meant to say "70 orders" instead of "50 orders". If so, then the equation r+c = 50 would be r+c = 70 and everything would lead to choice B as the final answer.

Choices C and D are similar to that of choice A, so they can be ruled out.

i think it is c, not positive though

step-by-step explanation:

in mathematics, a constraint is a condition of an optimization problem that the solution must satisfy. there are several types of constraints—primarily equality constraints, inequality constraints, and integer constraints. the set of candidate solutions that satisfy all constraints is called the feasible set.

hoped i'm right lol