The correct answer is (b), 65%.
To calculate the percentage of students obtaining more than 10 and less than or equal to 40 marks, we can use the following formula:
Percentage = (Number of students obtaining more than 10 and less than or equal to 40 marks) / (Total number of students) * 100%
In this case, the number of students obtaining more than 10 and less than or equal to 40 marks is 65. The total number of students is 100. Therefore, the percentage of students obtaining more than 10 and less than or equal to 40 marks is 65%.
Option (a), 15%, is incorrect because it is the percentage of students obtaining less than 10 marks. Option (c), 69%, is incorrect because it is the percentage of students obtaining more than 40 marks. Option (d), 74%, is incorrect because it is the percentage of students obtaining 40 marks or more.