SOLUTION: This is what I have but when I worked it out it was inconceivable so I know I did something wrong. Please help. Andrea Phil is making a Starbuck�s � run for his exhausted Math

Question 50206: This is what I have but when I worked it out it was inconceivable so I know I did something wrong. Please help. Andrea
Phil is making a Starbuck�s � run for his exhausted Math 105 classes. He is going to buy a combination of Lattes and Cappuccinos. The Lattes cost $4 each and the Cappuccinos cost $3 each. If he needs 30 drinks total and has $100 to spend, how many of each should he buy?
Lattes - $4 each - Quantity is x - Total is 4x
Cappuccinos - $3 each - Quantity is 30-x - Total is 3(30-x) or 90-3x
Mixture - $100 to spend - Quantity is 30 - Total is 3000
So then I said 4x+90-3x=3000
x=2910
I think I have the right idea but obviously it doesn't work.
Answer by mathchemprofessor(65) (Show Source): You can put this solution on YOUR website!
This is what I have but when I worked it out it was inconceivable so I know I did something wrong. Please help. Andrea
Phil is making a Starbuck�s � run for his exhausted Math 105 classes. He is going to buy a combination of Lattes and Cappuccinos. The Lattes cost $4 each and the Cappuccinos cost $3 each. If he needs 30 drinks total and has $100 to spend, how many of each should he buy?
Lattes - $4 each - Quantity is x - Total is 4x
Cappuccinos - $3 each - Quantity is 30-x - Total is 3(30-x) or 90-3x
Mixture - $100 to spend - Quantity is 30 - Total is 3000
So then I said 4x+90-3x=3000
x=2910
I think I have the right idea but obviously it doesn't work.

THE LAST FEW STEPS WILL BE AS FOLLOWS:
Total amount spent=4x +(90-3x)=100
4x-3x+90=100
x+90=100
Subtracting 90 on both sides, we get
x=100-90=10
So the number of Lattes bought=10 for 10($4)=$40
Number of Cappuccinos bought=30-10=20 for 20($3)=$60
OK?

RELATED QUESTIONS
i have the problem: ln(x+1)^2=2 i worked it out as: ln(x+1)^2=2 (x+1)^2=e^2... (answered by stanbon)

I am supposed to solve using the substitution method. 5x-6y=-20 5x+45=y Here is what... (answered by Alan3354,mananth,nerdybill)

This deals with average rate of change. I got answers but I have a feeling that they are... (answered by solver91311)

Hi. I'm an adult musician who sometimes uses mathy stuff to generate musical structures.... (answered by mangopeeler07,jim_thompson5910)

What is the the discriminant of 12x^2-x-6=0? I tried working it out and got an a long... (answered by scott8148)

I'm working a statistic problem and I have gotten up until this point 2.045 over 9 =... (answered by stanbon)

Mitsuko�s salary for next year is $44,940. This represents a 7% increase over... (answered by ewatrrr)

i have the problem: ln(x+1)^2=2 i worked it out as: ln(x+1)^2=2 (x+1)^2=e^2... (answered by Alan3354)

Ok, I just submitted this question so I am sorry for re-submitting it. x+7y=8 x=6-7y I (answered by checkley77)