Aplay is performed for a crowd of 400 people. adult tickets cost $22 each, student tickets cost $15 each, and tickets for children cost $13.50 each. the revenue for the concert is $7840. there are 40 more children at the concert than students. how many of each type of ticket are sold?

280 adult tickets, 40 student tickets and 80 children tickets were sold.

Step-by-step explanation:

To solve this problem let's call:

x = number of tickets for adults

y = number of tickets for students

z = number of tickets for children

The income for the concert is $ 7840

Then we can raise the following equations according to the given conditions:

  (i)

(ii)

 There are 40 more children in the concert than students:

So:

 (iii)

We then have 3 equations and 3 unknowns:

To solve the system we multiply the equation (i) by -22 and add it to the equation (ii)

So:

       +

(iv)

 Now we multiply (iii) by 7 and add it to (iv)

   +

(v)

We substitute (v) in (iv) and we have

(vi)

We substitute (v) and (vi) into (i) and we have:

280 adult tickets, 40 student tickets and 80 children tickets were sold.

what is the approximate angle of acb if abc is 25cm and the length of segment bc is 15

step-by-step explanation:

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.