1 15/24 : 1 2/3 =

Convert mixed numbers to improper fractions: 1 15/24 = 39/24, 1 2/3 = 5/3. Divide the fractions: (39/24) / (5/3) = (39/24) * (3/5) = (39 * 3) / (24 * 5) = 117 / 120. Simplify the fraction: 117/120 = 39/40. The answer is 39/40.