Movie Tickets

[nycmath]

A movie hall sold tickets to one of its shows in two denominations, 11 dollars and 7 dollars. A fourth of all those who bought a ticket also spent 4 dollars each on refreshments at the movie hall. If the total collections from tickets and refreshments for the show was 124 dollars, how many 7 dollars tickets were sold? Note: The number of 11 dollars tickets sold is different from the number of 7 dollars tickets sold.