Arop had eight rebounds with 3-of-7 3-point shooting while Cummings was 4 of 5 from long distance.
Khristian Smith's 3-pointer with 4:05 left in the first sparked a 30-9 Sycamores run that ended on Arop's 3-pointer and a 54-34 lead early in the second. During that run, Indiana State was 10 of 14 from the field, including 8 of 12 from 3-point range.
John Jones made two free throws with 4:15 left in the first to give Illinois State a 25-24 lead, but the Redbirds quickly fell behind and never challenged again.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.