The cost of renting a bus for a field trip was divided evenly among 20 students. At the last minute, 10 more students joined the trip. The cost of renting the bus was then redistributed and evenly split among all of the students. The cost for each of the original 20 students decreased by $1.50. What was the total cost of renting the bus, in dollars?

a.45

b.90

c.135

d.180

Guest Jul 10, 2019

#1**+3 **

I'm guessing A but you heed more info as in the amount of the 30 students or the twenty stdents

travisio Jul 10, 2019

#3**0 **

That's actually incorrect. By guess and check, the answer is b, as in the beginning each student pays $4.5 and afterwards each student pays $3.

Guest Jul 10, 2019

#5**0 **

x = original cost

price = 20x

New cost = x- 1.5

new total price is still 20x

30 * (x-1.5) = 20 x

30 x -45 = 20x

10x = 45

x = 4.5

20 (4.5 ) = 90

Guest Jul 10, 2019

#6**+2 **

x = original cost

price = 20x

New cost = x- 1.5

new total price is still 20x

30 * (x-1.5) = 20 x

30 x -45 = 20x

10x = 45

x = 4.5

20 (4.5 ) = 90

ElectricPavlov Jul 10, 2019

#8**+2 **

**The cost of renting a bus for a field trip was divided evenly among 20 students. **

**At the last minute, 10 more students joined the trip. **

**The cost of renting the bus was then redistributed and evenly split among all of the students. **

**The cost for each of the original 20 students decreased by $1.50. **

**What was the total cost of renting the bus, in dollars?**

\(\text{Let total cost $=c$} \\ \text{Let students $=s$} \\ \text{Let costs per student $c(s)=\dfrac{c}{s}$} \)

\(\begin{array}{|rcll|} \hline c(30) &=& c(20) - $1.50 \\\\ \dfrac{c}{30} &=& \dfrac{c}{20}- $1.50 \quad | \quad \cdot 30\\\\ c &=& 1.5c - $1.50\cdot 30 \\ c &=& 1.5c - $45 \\ 1.5c-c &=& $45 \\ 0.5c &=& $45 \\ c &=&\dfrac{ $45}{0.5} \\ \mathbf{c} &=& \mathbf{$90} \\ \hline \end{array}\)

The total cost of renting the bus, in dollars was **$90**

heureka Jul 11, 2019