In how many ways can 3 prefects be chosen out of 8 prefects?
Find the standard deviation of the numbers 3,6,2,1,7 and 5.
| Marks | 5-7 | 8-10 | 11-13 | 14-16 | 17-19 | 20-22 |
| No of students | 4 | 7 | 26 | 41 | 14 | 8 |
The table above shows the distribution of marks of students in a class. Find the upper class boundary of the modal class.
Four doctors and two nurses are to sit round a circular table. In how many ways can this be done if the nurses are to sit together?
