Answer:
8 vans
7 buses
Step-by-step explanation:
Let there be "b" buses
and "v" vans
Since 7 people is the capacity of vans, the total capacity is
7v
Also, since 25 people is the capacity of 1 bus, the total capacity is
25b
In total 231 people, so we can write our first equation as:
7v + 25b = 231
Now, we know there are 15 vehicles (bus + vans) in total, so we can write our 2nd equation as:
v + b = 15
Now, we solve for v and b. Let's solve the 2nd equation for v and substitute that into 1st and solve for b first:
v + b = 15
v = 15 - b
Now,
![7v + 25b = 231\\7(15-b) + 25b = 231\\105-7b+25b=231\\18b=126\\b=7](https://tex.z-dn.net/?f=7v%20%2B%2025b%20%3D%20231%5C%5C7%2815-b%29%20%2B%2025b%20%3D%20231%5C%5C105-7b%2B25b%3D231%5C%5C18b%3D126%5C%5Cb%3D7)
Hence, there are 7 buses
Since 15 vehicles in total, the number of vans is:
15 - 7 = 8 vans
So,
8 vans
7 buses