Nine friends are planning to attend a concert. If another friend also goes with them, they will get a group discount on their tickets. If the new total price of the tickets with the group discount is the same as the original total price of the tickets without the group discount, how much is the discount?	Choose the correct choice
A) 5%
B) 10%
C) 20%
D) 25%
E) 33%
Let x be the original price of one ticket.   The total original cost is 9x.   The new cost is 10y, where y is the discounted price of one ticket.   9x = 10y   y = 9x/10 = 0.9x which is a discount of 10%.   The answer is 10%.9 /10= 
<gadget id="calculator">9 /10</gadget>
<output>9/10 = around 0.9</output>
0.9x which is a discount of 10%.   The answer is 10%.
<result>B</result>
Nine friends are planning to attend a concert. If another friend also goes with them, they will get a group discount on their tickets. If the new total price of the tickets with the group discount is the same as the original total price of the tickets without the group discount, how much is the discount?