Question Number 103357 by bobhans last updated on 14/Jul/20

There are 21 students will be trained  with 6 trainers available. Every students  is trained by 1 coach and every coach  trains students with different amounts.  many ways of grouping students who  will be trained are ....  (a) ((21!)/(6!))    (b) 6!.21!     (c) ((21!)/(2!.3!.4!.5!  ))    (d) 6×21!    (e) ((21!)/(15!))×6!

Answered by bemath last updated on 14/Jul/20

⇔ ((21!)/(1!.20!)) ×((20!)/(2!.18!))×((18!)/(3!.15!))×((15!)/(4!.11!))  × ((11!)/(5!.6!))×((6!)/(6!.0!)) ×6! = ((21!)/(2!.3!.4!.5!))

Commented bybobhans last updated on 15/Jul/20

nice !! ⌣∴⌣