To calculate the number of combinations for n distinguishable items: Three laboratories to be cleaned: Biosorption, Pilot Plant and Fermentation. How many different combinations of cleaning the three laboratories? n=3, r=2 1st 2nd Not done B P F B F P P B F P F B 3 different combinations F B P F P B
To calculate the number of permutations for n distinguishable items: Three laboratories to be cleaned: Biosorption, Pilot Plant and Fermentation. How many different sequences of cleaning the three laboratories? n=3, r=2 1st 2nd Not done B P F B F P P B F P F B 6 different sequences F B P F P B
} } } To calculate the number of permutations with classes: There are three blocks to be ranged and two (No.#2 and No#3) of them are the same. How many orders can the three blacks be arranged? n=3, r=3, n1=1, n2=2 1 2 3 } same, 1st arrangement 1 3 2 2 1 3 } 2nd arrangement 3 1 2 2 3 1 } 3rd arrangement 3 2 1