71.

The angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary. The height of the tower is:

• 4 m

• 7 m

• 9 m

• 6 m

Study the histogram of marks (in Mathematics) distribution of 50 students of class IX and answer the following questions.

The number of students who have secured marks less than 60 is:

• 12

• 15

• 33

• 33

Study the histogram of marks (in Mathematics) distribution of 50 students of class IX and answer the following questions.

The average marks of the students are

• 63.2

• 45.5

• 60.2

• 60.2

Study the histogram of marks (in Mathematics) distribution of 50 students of class IX and answer the following questions.

The number of students who have scored between 39 and 80 is

• 22

• 18

• 37

• 37

Study the histogram of marks (in Mathematics) distribution of 50 students of class IX and answer the following questions.

Percentage of students who have secured marks more than 59 is:

• 13%

• 17%

• 34%

• 34%