(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

in how many different ways can 7 different books be arranged in a row if

a. 3 specified books must be together,

b. two specified boks mus occupy both ends

2. Relevant equations

i dont udnerstand wether it is a permutation or a combination.

3. The attempt at a solution

a. 4! x 7!

b. 7 x 5! x 6

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Permutation or combination

**Physics Forums | Science Articles, Homework Help, Discussion**