Statement 1 could be correct. If 70% swim and 40% climb, this takes the total to 110 (70 + 40 = 110%). This is not possible as the maximum can only be 100%. Therefore, at least 10% of the people would do swimming and climbing. (110% – 100% = 10%). We know therefore that some members must be doing both. This would mean 60% swim only, 10% do both and 30% climb only.
Statement 2 could be correct. We have already established that at least 10% must be doing both swimming and climbing. Some people would be swimming only and other would be climbing only. So all members are either swimming or climbing or doing both.
Statement 3 could be correct. Half of members who climb = 40% ÷ 2 = 20%
We know that there is a possibility where 30% of members climb only. So this statement can also be correct.
So A is the answer.