N = number of nights
M = number of meals
n = cost per night
m = cost per meal
T = total cost
Nn + Mm = T
They give us two scenarios :
1. N = 3 and M = 1 and T = 250
3n + 1m = 250
2. N = 3 and M = 6 and T = 330
3n + 6m = 330
Thus, we have a system of equations.
In the first equation, solve for m.
m = 250 - 3n
Now, plug this into the second equation and solve for n.
3n + 6m = 330
3n + 6(250 - 3n) = 330
3n + 1500 - 18n = 330
-15n = -1170
n = $78
Now, plug this back into our equation for m and solve.
m = 250 - 3n
m = 250 - 3(78)
m = 250 - 234
m = $16
Thus, it costs $78 per night and $16 per meal.