Seven songs are to be rendered in a programme. In how many different orders could they be rendered?

Carnallite consists of how many different compounds ?

Six papers are set in examination, two of them in mathematics: in how many different orders can the papers be given, provided only that the two mathematical papers are not successive?

A triglyceride can have how many different acyl groups?

Satish and Mukesh who live in London wish to go on a holiday to France . They can travel to the coast by car , coach or train , and then cross the channel by ferry , train , helicopter or hovercraft. How many different ways could they travel ?

A local card club will send 3 representatives to the national conference. If the the local club has 8 members, how many different groups of representatives could the club send?

The genes controlling the seven pea characters studied by Mendel are now known to located on how many different chromosomes?

The single stranded DNA of phage phixx174 has 5400 nucleotides. If average protein contains 200 amino acids, how many different proteins could this phage DNA code?

Pure (+) 2 - chlorobutane gives how many different dichlorbutanes?

A postman has to deliver five letters to five different houses. Mischievously, he posts one letter through each door without looling to see if it is the correct address. In how many different ways could he do this so that exactly two of the five houses receive the correct letters?