The greatest coefficient in the expansion of (x+y+z+t)15 is
15!3!(4!)2
15!3!4!
5!3!(4!)3
15!3!(4!)3
greatest coefficient =n!(q!)m−r((q+1)!)r
where q is quotient and r is remainder when n is divided by m. Here n = 15 and m =4
q=3 And r = 3
So coefficient =15!3!(4!)3