Kak gimana ini? Tolong dijawab ya plis.. Karena PR Ku banyan

1.
a.{b,c,d,f,g,h,j,k,l,m,n,p,q,r,s,t,v,w,x,y,z}

b. {1,2,3,4,5,6,7,8,9}

c. {3,6,9,12,15,18,21,...99}

d. {11,12,13,14,15...100}