Six men and three women are standing in a supermarket queue.
The diagram shows the seating plan for passengers in a minibus, which has 17 seats arranged in 4 rows. The back row has 5 seats and the other 3 rows have 2 seats on each side. 11 passengers get on the minibus.
A staff car park at a school has 13 parking spaces in a row. There are 9 cars to be parked.
A group of 15 friends visit an adventure park. The group consists of four families.
The group enter the park by walking through a gate one at a time.
In how many different orders can the 15 friends go through the gate if Mr Lizo goes first and each family stays together?
A group of 12 people consists of 3 boys, 4 girls and 5 adults.
How many different arrangements are there in which the 3 boys stand together and an adult is at each end of the line?