A can complete 3/8 part of a work in 36 days. B can complete 1/2 part of the same work in 27 days. Which of the following statement(s) is/are correct? I. A is less efficient than B. II. A and B working together can complete 11/15 part of the same work in 36 days.

A completes 3/8 work in 36 days, so 1 work in 36 × 8/3 = 96 days. B completes 1/2 work in 27 days, so 1 work in 27 × 2 = 54 days. A takes 96 days, B takes 54 days, so A is less efficient (slower) - Statement I is correct. Together in 1 day: 1/96 + 1/54 = 3/288 + 5.33/288 ≈ 8.33/288. In 36 days: 36 × 8.33/288 ≈ 1.04 work, not 11/15 (0.73). So II is false. Only I is correct.