There are 6 periods in each working day of a school. The number of ways one can arrange 5 subjects such that each is allowed at least one period, is

Step-by-step solution

First of all we can choose the subject which is to be repeated twice in ^5 C₁ ways Now 6 subjects with one repeation can be arranged among 6 periods in 6 ! 2 ! Hence, total number of ways ^5 C₁ 6 ! 2 ! =1800