The present ages of A and B are in the ratio 4:5 and after 5 years they will be in the ratio 5: 6. Then the present age of A is.
The average age of 9 students and their teacher is 16 years . The average age of the first four students is 19 years and that of the last five is 10 years. The teacher’s age is.
The average age of A and B is 30 years and that of B and C is 26 years. The difference of the age of A and C is.
In a school with 600 students, the average age of the boys is 12 years and that of the girls is 11 years. If average age of the school is 11 years and 9 months, then the number of...