a=matrix(runif(10),2,5)
b=matrix(runif(15),3,5)

c=matrix(,nrow(a)*nrow(b),5)
k=0
for(i in 1:nrow(a)){
  for(j in 1:nrow(b)){
    k=k+1
    c[k,]=a[i,]*b[j,]
  }
}