So how much does she spend in all right
I can't understand your question do you have any number there?
Answer:
See explanation
Step-by-step explanation:
Let
be the number of students and
be the number of adults on the show.
1. Tickets cost $15 for students, so x student tickets cost $15x.
Tickets cost $25 for adults, so y adult tickets cost $25y.
Total cost of all tickets is $(15x + 25y).
The charity show is conducted in order to raise at least $3,750, thus

2. The auditorium can accommodate up to 180 spectators, hence

3. We get the system of inequalities:

Plot all solutions sets to each inequality and the common region is the solution set to the system of inequalities. This region is not empty, so the charity will reach its goal. For example, if they sell 50 students tickets and 125 adult tickets, they will raise 
Well its $16
for 4 tickets so u multiply everything by four and get $64 for 16 tickets
Answer:
the cyclists rode at 35 mph
Step-by-step explanation:
Assuming that the cyclists stopped, and accelerated instantaneously at the same speed than before but in opposite direction , then
distance= speed*time
since the cyclists and the train reaches the end of the tunnel at the same time and denoting L as the length of the tunnel :
time = distance covered by cyclists / speed of cyclists = distance covered by train / speed of the train
thus denoting v as the speed of the cyclists :
7/8*L / v = L / 40 mph
v = 7/8 * 40 mph = 35 mph
v= 35 mph
thus the cyclists rode at 35 mph