Greatest coefficient in the expansion of (a+b+c+d)10 is

Greatest coefficient in the expansion of x1+x2+…xkn is n!(q!)k-r((q+1)!)r, Where q= Quotient of nk,r= Reminder of nk In the expansion (a+b+c+d)10n=10;k=4⇒q=2,r=2∴ Greatest coefficient is 10!(2!)2(3!)2