282.5 of 10 tickets were sold in the rock concert by the promoter
How to determine the number of 10 tickets?
To do this, we make use of the following representations:
- x represents the 10 tickets
- y represents the 15 tickets
- z represents the 20 tickets
The 475 tickets that were sold means that:
x + y + z = 475
The income means that:
10x + 15y + 20z = 6300
Also, we have:
10y = 4z
Divide both sides by 10
y = 0.4z
Substitute y = 0.4z in 10x + 15y + 20z = 6300
10x + 15*0.4z + 20z = 6300
10x + 6z + 20z = 6300
Evaluate the like terms
10x + 26z = 6300
Substitute y = 0.4z in x + y + z = 475
x + 0.4z + z = 475
Evaluate the like terms
x + 1.4z = 475
Make x the subject
x = 475 - 1.4z
Substitute x = 475 - 1.4z in 10x + 26z = 6300
10(475 - 1.4z) + 26z = 6300
Expand
4750 - 14z + 26z = 6400
Evaluate the like terms
12z = 1650
Divide both sides by 12
z = 137.5
Substitute z = 137.5 in x = 475 - 1.4z
x = 475 - 1.4 * 137.5
Evaluate
x = 282.5
Hence, 282.5 of 10 tickets were sold
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