Martin bought 10 concert tickets, some at the full price of $2.00 per ticket, and some at a discounted price of $1.60 per ticket. If he spent a total of $18.40, how many discounted tickets did he buy? Choose the correct choice:
A) 3  B) 4  C) 5  D) 6  E) 7
Let x be the number of tickets he bought at $2 per ticket.   then 2 x + (10-x)1.6 = 18.4   0.4x = 2.4 =&gt; x = 6   discounted tickets = 10 -x = 4   Ans : 4
<result>B</result>
Martin bought 10 concert tickets, some at the full price of $2.00 per ticket, and some at a discounted price of $1.60 per ticket. If he spent a total of $18.40, how many discounted tickets did he buy?