In an examination, 40% of the candidates write their answers in Urdu and the rest in Marathi. The average marks of the candidates writing in Urdu is 74 and the average marks of the candidates writing in Marathi is 77. What are the average marks of all the candidates? 

The average age of a husband and wife, who were married 4 years ago, was 25 years at the time of their marriage. The average age of the family consisting of husband, wife and a child, born during the interval is 20 years today. The age of the child is:

 In a family, the average age of a father and a mother is 35 years. The average age of the father, mother and their only son is 27 years. What is the age of the son? 

The average age of a husband and his wife was 27 years when the child was born, the average age of the husband, the wife and new-born child is 21 years now. The present age of the child is:

Average weight of 25 students of a class is 50 kg. If the weight of the class teacher is included, the average is increased by 1 kg. The weight of the teacher is 

The average monthly salary of all the employees in an industry is Rs. 12,000. The average salary of male employees is Rs. 15,000 and that of female employees is Rs. 8,000. What is the ratio of male employees to female employees?

The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 grams. Find the weight of the teacher (in kg.) 

The average mathematics marks of two Sections A and B of class IX 131 the annual examination is 74. The average marks of Section A is 77.5 and that of Section B is 70. The ratios of the number of students of Section A and B is: