Orange-Grapefruit Salad
["1 (6 oz.) pkg. orange gelatin", "1 1/2 c. boiling water", "1 (6 oz.) can frozen orange juice, thawed", "1 c. cold water", "1 (11 oz.) can mandarin oranges", "1 lb. can grapefruit sections, drained and cut in pieces"]
["Dissolve gelatin in boiling water.", "Add orange juice concentrate and cold water.", "Drain oranges, reserving syrup.", "Add syrup to gelatin mixture.", "Chill until partially set.", "Fold in oranges and grapefruit.", "Pour into 6 1/2-cup ring mold.", "Chill until set.", "Unmold.", "Serve with mayonnaise."]
["orange gelatin", "boiling water", "orange juice", "cold water", "mandarin oranges", "grapefruit sections"]