Sum of the coefficients of terms of degree 13 in the expansion of (1+x)111+y2−z10 is

Required sum of coefficients                 = coefficient of t13 in (1+t)111+t2−t10                 = coefficient of t13 in (1+t)1+t310                 = coefficient of t13 in 1+t310+t1+t310                 = coefficient of t12 in 1+t310                 =10C4