Question 157 Problem Solving 2018 GMAT Quantitative Review

Question 157 Problem Solving 2018 GMAT Quantitative Review

Video explanation: There are 10 books on a shelf, of which 4 are paperbacks and 6…

Comments

Jennifersays

Hello ! I was watching the solution you posted and that obviously is the shortest way! However what if we were to check each individual arrangement. That means if I were to opt for the 1P,4H … 4P,1H sequence, how can I solve the last one ?

I got the following values for the 1st three arrangements : 60+120+60

The last one show be 6. But is this solution correct ?
For the arrangement 4P,1H
(4!/4!) x (6!/1!*5!)

Jennifer says

Hello ! I was watching the solution you posted and that obviously is the shortest way! However what if we were to check each individual arrangement. That means if I were to opt for the 1P,4H … 4P,1H sequence, how can I solve the last one ?

I got the following values for the 1st three arrangements : 60+120+60

The last one show be 6. But is this solution correct ?

For the arrangement 4P,1H

(4!/4!) x (6!/1!*5!)