In a certain school, the number of students in each section was 24. After admitting some students, three new sections have been started and now there are 16 sections with 21 students in each. What is the number of newly admitted students?

How many even integers between 4000 and 7000 have four different digits?

The average marks of boys in a class is 52 and that of girls is 42. The average marks of boys and girls combined is 50. The percentage of boys in the class is

The students in three classes are in the ratio 2 : 3 : 5. If 20 students are increased in each class, the ratio changes to 4 ∶ 5 ∶ 7. The total number of students before the increase were

There are five different boxes of different unknown weights each less than 100 kg. These boxes were weighted in pairs and the weights obtained are 110, 112, 113, 114, 115, 116, 117, 118, 120 and 121 kg. 

Father is aged three times more than the age of his son Rohit. After 8 yr, he would be two and a half of Rohit's age. After further 8 yr, how many times would he be of Rohit's age?

A watch gains 10 s in 5 min was set correct at 9.00 am. When the watch indicated 20 min past 7.00 pm in the same evening, the correct time is

The sum of ages of a daughter and mother is 63 yr. Four years back, the mother's age was 4 times that of daughter's age at that time. What is the present age of the mother?