In a class of 100 students. there are 70 boys whose average marks in a subject are 75. If the average marks of the complete class is 72, then what is the average of the girls?

Solution :

Since, total number of students = 100

and number of boys = 70

\(\therefore\) number of girls = (100 โ€“ 70) = 30

Now, the total marks of 100 students = 100*72 = 7200

And total marks of 70 boys = 70*75 = 5250

Total marks of 30 girls = 7250 โ€“ 5250

\(\therefore\)ย  Average marks of 30 girls = \(1950\over 30\) = 65


Similar Questions

The mean and variance of a random variable X having a binomial distribution are 4 and 2 respectively, then P(X = 1) is

The median of a set of 9 distinct observations is 20.5. If each of the largest 4 observation of the set is increased by 2, then the median of the new is

The mean and the variance of a binomial distribution are 4 and 2, respectively. Then, the probability of 2 success is

In a series of 2n observations, half of them equals a and remaining half equal -a. If the standard deviation of the observation is 2, then |a| equal to

A random variable X has poisson distribution with mean 2. Then, P(X > 1.5) equal to

Leave a Comment

Your email address will not be published. Required fields are marked *

Ezoicreport this ad