The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?

The average of runs of a cricket player of 10 innings was 32.How many runs must he make in his next innings so as to increase his average of runs by 4 ?

X sells 6 horses and buys 9 Cows, thus in creasing his cash by Rs 90. He then at the same prices buys 9 horses and sells 15 Cows, thus decreasing his cash by Rs 91. Find the price of each Cow.Assume he had nil balance at the start.

The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?

At a certain fast food restaurant, Brian can buy 3 burgers, 7 shakes, and one order of fries for Rs. 120 exactly. At the same place, it would cost Rs. 164.5 for 4 burgers, 10 shakes, and one order of fries. How much would it cost for an ordinary meal of one burger, one shake, and one order of fries ?

A trader mixes three varieties of groundnuts costing Rs. 50, Rs. 20 and Rs. 30 per kg in the ratio 2 : 4 :  3 in terms of weight, and sells the mixture at Rs. 33 per kg. What percentage of profit does he make?

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 tradesman gives 4% discount on the marked price and gives 1 article free for buying every 15 articles and thus gains 35%. The marked price is above the cost price by:

In a test, a candidate secured 336 marks out of maximum marks "x", If the maximum marks 'x'were converted into 400 marks, he would have secured 192 marks. What were the maximum marks of the test?

The average age of 30 students is 9 years .If the age of their teacher is included ,it becomes 10 years . The age of the teacher (in years ) is