There are 20 students in a Chemsitry class and 30 students in a Physics class. `.Find the number of students which are either in physics class or chemistry class in the following cases (i)Two classes meet at the same hour.

Which of the following class of compounds shows metamerism?

Identify the class of enzyme which catalyse the following reaction

60 % of the students in a class are boys. If the number of girls in the class is 20 , what is the total number of students?.

The average marks of 30 students in a class was 80. After two students left out of the class, the average marks of the remaining students was 82. Then the average marks of the two left out students is

There are 100 sstudents in a college class of which 36 are boys studying statistics and 13 girls not studying statistics. There are 55 girls in all. Suppose a students is picked up at random form the class. Then match the following

The mean and standard deviation of marks obtained by 50 students of a class in three subjects , mathematics ,Physics and Chemistry are given below : Which of the three subject shows the highest variability in marks and which shows the lowest?