If a pile of coal is transported by 2 large trucks and 3 small trucks, it can be transported 16 times. If 5 large trucks and 2 small trucks are transported 8 times, it can be transported completely. Now use 4 large trucks to transport it, how many times can it be transported.
运一堆煤，2辆大卡车和3辆小卡车运，16次可以运完，如果5辆大卡车和2辆小卡车运8次可以运完．现在用4辆大卡车运，多少次可以运完．
<result>11</result>