randomDisc(numPoints):= block([p: []],
  local(goodp, random_int),
  goodp(x, y):=block([r: sqrt(x^2+y^2)],
    r>=10 and r<=15
    ),
  random_int():= block([m: 15], m - random(2*(m+1)-1)),
  while length(p)<numPoints do block (
    [x: random_int(), y : random_int()],
    if goodp(x, y) then (
      p: cons([x, y], p)
      )
    ),
  p)$

p: randomDisc(100)$
plot2d(['discrete, p], ['style, 'points]);