Answer:
He sold 200 lower floor tickets.
Step-by-step explanation:
Consider the provided information.
Pierre sold 340 tickets for a concert.
Let Balcony tickets represents by x and lower floor ticket represents by y.
As we know he sold 340 tickets in total, i.e.
x + y = 340 ......(1)
Balcony tickets cost $5 while tickets for the lower floor cost $10.
If he sold x balcony tickets, so the money he got after selling x balcony tickets is 5x. Similarly, If he sold y lower floor tickets, so the money he got after selling y lower floor tickets is 10y.
Pierre sold $2,700 worth of tickets, i.e.
5x + 10y = 2700 ......(2)
Now use elimination method to solve the system of equations:
Multiply the equation (1) with 5 and subtract them as shown below:
5x + 5y = 1700
5x + 10y = 2700
_____________
-5y = -1000
y = 200
Thus, he sold 200 lower floor tickets.