If the average of 20 numbers is zero, how many numbers may be greater than zero?

A grocer has a sale of Rs 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs 6500?

The average marks in mathematics scored by the pupils of a school at the public examination were 39. If four of these pupils who actually scored 5, 12, 15 and 19 marks at the examination had not been sent up, the average marks for the school would have been 44. Find the number of pupils sent up for examination from the school?

A car owner buys petrol at Euro 7.50, Euro 8 and Euro 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Euro 4000 each year?

The average mark of a class in a science test is $75.$ Geetha was the topper with $96$ marks. If her mark was wrongly entered as $69,$ the average of the class decreases by $1$. Find the number of students in the class?

In the first 10 overs of a cricket game, the run rate was only 3.2. What should be the run rate in the remaining 40 overs to reach the target of 282 runs?

A team of eight entered for a shooting competition. The best marks man scored 85 points. If he had scored 92 points, the average scores for. The team would have been 84. How many points altogether did the team score?

The avergae of weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg.What might be the weight of new person?

The average of Sohan’s marks in 6 subjects is 74. If his average in five subjects excluding science is 70, how many marks he obtained in science?

In Arun’s opinion, his weight is greater than 65 kg but less than 72 kg. His brother doest not agree with Arun and he thinks that Arun’s weight is greater than 60 kg but less than 70 kg. His mother’s view is that his weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Arun?

The mean weight of a group of seven boys is 56 kg. The individual weights (in kg) of six of them are 52, 57, 55, 60, 59 and 55. Find the weight of the seventh boy.

The average height of 30 boys was calculated to be 150 cm. It was detected later that one value of 165 cm was wrongly copied as 135 cm for the computation of the mean. Find the correct mean.

The aggregate monthly expenditure of a family was $ 6240 during the first 3 months, $ 6780 during the next 4 months and $ 7236 during the last 5 months of a year. If the total saving during the year is $ 7080, find the average monthly income of the family.

The average of 52 numbers is 45. if two numbers, namely, 55 & 45 are discarded from the set of number, then find average of the remaining numbers.

The average of ten numbers is 15. If each number is multiplied by 12, then find the average of the new set of numbers.