2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/169119We prove Newton's binomial formulas for Schubert Calculus to determine numbers of base point free linear series on the projective line with prescribed ramification divisor supported at given distinct points.21 pages, no figures. To appear on "Revista Matemática Complutense". Dedicated to Israel Vainsencher on the occasion of his 60th birthdayAlgebraic GeometryCombinatorics14M15; 14N15; 15A75text