| 
 
 
| Question 1101033:  A stadium has 48,000 seats. Seats sell for $28 in section A, $16 section B, $12 section C. The numbers of seats in section A equals the total number of seats in section B and C. Suppose the stadium takes $1,016,800 from each sold-out event. How many seats does each section hold?
 Answer by ikleyn(52879)
      (Show Source): 
You can put this solution on YOUR website! . A stadium has 48,000 seats. Seats sell for $28 in section A, $16 section B, $12 section C.
 The numbers of seats in section A equals the total number of seats in section B and C. Suppose the stadium takes $1,016,800
 from each sold-out event. How many seats does each section hold?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 
 
Let x be the number of seats in section B, and y be the number of seats in section C.
Then the number of seats in section A is x+y, the sum of seats in sections B and C, according to the condition.
The condition says
seatsA + seatsB + seatsC = 48000,   or
(x+y)  + x      + y      = 48000,   which is the same as
2(x+y) = 48000,                     which implies
x + y =  = 24000.
Thus we found that the sum of seats in sections B and C is 24000,  
and, therefore, the number of seats in section A is 24000.
Thus we have now the problem  FOR TWO UNKNOWNS only, since we just excluded A.
Now our system of two equations is
  x +   y = 24000,                  (1)
16x + 12y = 1016800 - 28*24000.     (2)   
Equation (2) express the money payed for seats in sections B and C together.
Simplify (1),(2) step by step:
  x +   y = 24000,                  (3)
16x + 12y = 344800.                 (4)
Multiply eq(1) by 16 (both sides). Then subtract eq(2) from it:
16x + 16y = 384000,                 (3)
16x + 12y = 344800.                 (4)
-------------------------
====> 4y = 384000-344800 = 39200  ====>  y =  = 9800.
Then  x = 24000 - y = 24000 - 9800 = 14200.
Answer.  There are 24000 sears in section A,  14200 in section B  and  9800 in section C. 
 
 | 
  
 | 
 |