SOLUTION: Some students planned for a get-together. The budget for food was $500. Five of the students failed to come because of the distance and therefore the cost of food for each member i

Algebra.Com
Question 170726This question is from textbook intermediate algebra
: Some students planned for a get-together. The budget for food was $500. Five of the students failed to come because of the distance and therefore the cost of food for each member increased by $5. How many students attended the get-together?
Not sure how to do these word problems and will appreciate any help, so far I have a B in class :)
This question is from textbook intermediate algebra

Found 2 solutions by jim_thompson5910, Mathtut:
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Let c=cost per individual (the cost before the students failed to arrive) and n=number of students


So the total cost is divided among n people to get




Since 5 failed to attend, this means that students showed up. Now the new cost is




Start with the given equation.


Plug in


Multiply every term by the LCD . This cancels out every denominator.


Distribute


Subtract from both sides.


Subtract from both sides.


Let's use the quadratic formula to solve for n


Start with the quadratic formula


Plug in , , and


Negate to get .


Square to get .


Multiply to get


Rewrite as


Add to to get


Multiply and to get .


Take the square root of to get .


or Break up the expression.


or Combine like terms.


or Simplify.


Since a negative amount of people doesn't make any sense, this means that the only answer is


So 25 people were going to attend but only 20 actually attended.

Answer by Mathtut(3670)   (Show Source): You can put this solution on YOUR website!
alright so we would normally find out an average cost per person by taking the cost and dividing by number of people....lets call the original # of people attending x so avg cost would be 500/x but now x is decreasing by 5 and the average cost is increasing by 5 so
:
mulitply all terms by x(x-5)
:

:
500x-2500=500x-5x^2+25x}}}
:
divide by 5
:

:

:
throw out the negative and we have the original amount of people of 25
:
therefore the number of people attending the party is
:
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=2025 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 25, -20. Here's your graph:



RELATED QUESTIONS

Some students planned a get-together. The budget for food was $500. Five of the... (answered by stanbon)
This is an online study course. Some students planned for a get-together. The budget... (answered by stanbon,ankor@dixie-net.com)
Some students planned for a get-together. The budget for food was $500. Five of the... (answered by stanbon)
Desparate need of help. Thank you in advance! Some students planned for a... (answered by ankor@dixie-net.com)
Some students planned for a get-together. The budget for food was $500. Five of the... (answered by Paul)
Some students planned for a get-together. The budget for food was $500. Five of the... (answered by khwang)
Hello. I have been workingon this problem all night and I know it's probably something (answered by longjonsilver)
Some students planned for a get-together. The budget for food was $500. Five of the... (answered by Paul)
Guidance it needed with this problem please. "Some students planned for a... (answered by ankor@dixie-net.com)