Solution : We have given Four children anne,jordan,david & katie are to be seated in a single row on a bench. Now to find sitting arrangements we need to put first Anne in the left, so, there will be two possible ways for Anne to sit:
Anne, child, child, child
child, Anne, child, child.
Then we must have in mind also that in each place we should put one of the 3 children left so there will be 2 times 3! ways of arrange them.
If the question say's left and means that 'left with respect to all others' then it is just the first case and we will have 1 times 3! ways to arrange them.
Anne, child, child, child.