While purchasing one item costing Rs.400, one has to pay sales tax at 7 % and on another costing Rs. 6400, the sales tax was 9%. The percentage of sales tax one has to pay, taking these items together on an average is: 

The average weight of 5 men is increased by 4 kg. If one of them who weigh 121 kg is replaced by another man, then what is the weight of the new man? 

Average age of 6 boys is 14 years. Average age of 11 girls is 12 years. What is the average age (in years) of all boys and girls?

The average of a collection of 20 measurements was calculated to be 56 cm . But later it was found that a mistake had occurred in one of the measurements which was recorded as 64 cm, but should have been 61 cm. The correct average must be: 

The average marks of a student in an examination is 63, if he had scored 20 marks in geography and 2 more marks in history, his average marks would have been 65. How many subjects were there in the exam?

In the first 10 overs of a cricket game, the run rate was only 3.2. The run rate in the remaining 40 overs to reach the target of 282 runs is –

There are 1600 students in a college, whose average weight is 50 kg. If average weight of boys is 54 kg. and average weight of girls is 38 kg. Then find the number of girls in the school.

The average weight of 24 students is 35 kg. If the weight of teacher is added the average increased by 400 gram. What is the weight of the teacher?