Ten people are boarding an aircraft.Two have tickets for first class and board before those in the economy class.In how many ways can the ten people board the aircraft?
A)240
B)48
C)80,640
D)12
E)1,440

Question

Ten people are boarding an aircraft.Two have tickets for first class and board before those in the economy class.In how many ways can the ten people board the aircraft? ​
A)240
B)48
C)80,640
D)12
E)1,440

Quizplus · Accepted Answer

The two people with first class tickets can board in $2$ ways. Then, the remaining $8$ people in economy class can board in $8!$ ways. Therefore, the total number of ways the ten people can board the aircraft is $2 \cdot 8!=80,640$.

Ten People Are Boarding an Aircraft