# Maths

posted by .

The teacher collected the test papers of 20 students and found that their average mark was 15. Before she wrote the marks in her mark book, she lost 1 paper. Find the mark for the missing paper, she worked out the average mark for the 19 students was 14. What was the mark on the missing paper?

• Maths -

Σx/n = mean

for 19 students Σx = 19 * 14 = 266

(266 + x)/20 = 15

Solve for x.

• Maths -

-231

## Similar Questions

1. ### English

1. There is a seal mark on the piece of paper,for I pressed the seal on the piece of paper. 2. There is a seal on the piece of paper,for I pressed the seal on the piece of paper. (Which one is correct?
2. ### maths

these marks were obtained by class of 28 students in a science test. the maximum mark possible is 25. 20,17,21,15,16,15,12,14,15,19,21,17,20,22,16,19,21,13,22,15,14,18,20,13,18,16,15,19. a.calculate the mode b.what would you give as …
3. ### physics

A tank filled with water has marks every 10 cm on one wall. The refractive index is 1.33 for water in the tank. You observe the marks out in air, from the opposite wall and with your eye level with the top of the water. Which is the …
4. ### statistics

The average marks of 30 students in mathematics is 69. If the class leader’s mark is included then the average becomes 70. Find the class leader’s mark.
5. ### math

The difference between Sally’s PE mark and science mark is 12, and the sum of the marks is 154. If the PE mark is the larger mark, what did Sally get for each subject?
6. ### math

Sammy got an average of 85% in four tests threethree of the scores were 79 97 85 find the fourth mark if he wrote a fifth test his average increase by 3 what is his fifth mark
7. ### math

A test consists of 120 questions. Each correct answer, each wrong answer and unanswered question in the test carry 1 Mark, 0.5 Mark and 0.25 Mark respectively. Find the maximum number of questions that the candidate could have answered …
8. ### programming

draw a flow chart and write algorithms description that accept three mark of students and print the mark which greater than the average mark of the students?
9. ### MATHS

THE AVERAGE MARK OF 4 GIRLS IN A SCIENCE TEST IS 6,THE MARKS OF 3 OF ZM ARE 5,7,4.FIND THE MARK OF THE 4TH GIRL.
10. ### Math

In aclass of 100 students the average mark in math paper is 60.the average mark for the top 30 students is 80.find the average mark for the remainning 70 students.

More Similar Questions