Answer:
0.430
Step-by-step explanation:
Product has four parts :
For proper functioning, each part must function :
Let the 4 parts be:
A, B, C and D
Proper functioning probability :
A and B = 0.79
C and D = 0.83
For proper functioning :
P(A) * P(B) * P(C) * P(D)
0.79 * 0.79 * 0.83 * 0.83
= 0.42994249
= 0.430
Your equation should be
$4(40 tickets) + $5(X) = $400
160 +5x = 400
-160 -160
0 5x = 340
divide both sides by 5
5x/5 = 340/5
x = 68
so they need to sell 68 tickets at the door.
4(40) + 5(68) = 400
160 + 340 + 400
400 + 400
<span>=<span>14/15</span></span><span>(Decimal: 0.933333)</span>