Question
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?
Answers
PsyDAG
Σx/n = mean
for 19 students Σx = 19 * 14 = 266
(266 + x)/20 = 15
Solve for x.
for 19 students Σx = 19 * 14 = 266
(266 + x)/20 = 15
Solve for x.
moksha
-231