The mean income of a group of workers is `bar(X)` and that of another group is `bar(Y)`. If the number of workers in the second group is 10 times the number of workers in the first group, then the mean income of the combined group is

The average income of a group of persons is vec x and that of another group is vecy. If the number of persons of both group are in the ratio 4 : 3, then average income of combined group is:- (1) (vec x + vec y)/7 (2) (3vec x + 4 vec y)/7 (3) (4 vec x + 3vec y)/7 (4) Non of these

The average income of a group of 9 workers is Rs 137.30 and that of another group of 7 workers is rs 95.06. The average income of all the persons is:

Boron is the first element of group 13. Name the second element of this group.

Lithium is the first metal of group 1. Name the second and third metals of this group.

The mean age of a combined group of men and women is 30 years. If the mean age of the group of men is 32 and that of the group of women is 27, find the percentage of men and women in the group.

The average salary of managers is x and the average salary of workers is y. The number of the managers is 15 times of the number of workers. What is average salary of managers and workers together?

Use shortcut method to find the mean of monthly wages of a certain number of workers: Find the new mean, when: the number of workers in each category is halved.