A mathematics teacher calculated the total marks obtained by 35 students of 8th class . The average marks of the students were 72. But 36 marks for Reena was calculated in place of 86 obtained by her. What was the correct average of all the students? 

15 person can complete a work in 60 days. If the number of persons is increased by 5, how many days earlier will the work get completed?

What is total surface area of a cone where, r’ is radius and ‘l’ is slant height?   

Directions: Each of the questions consists of a question followed by three statements. You have to study the questions and the statements and decide which of the statements(s) is/are necessary to answer the question. 

What was the percentage of discount offered?
 I. Profit earned by selling the article for Rs. 252 after giving discount was Rs. 52.
 II. Had there been no discount the profit earned would have been Rs. 80
 III. Had there been no discount the profit earned would have been 40%.

Ramesh stands 40 meters away from the foot of a tower, if the angle of elevation of the sun is 60 degrees at that point, what will be the height of the tower?

Cost of a diamond varies directly as the square of its weight. A diamond broke into four pieces with their weights in the ratio 1 : 2 : 3: 4. If the loss in the total value of the diamond was Rs.7000, the price of the original diamond was

Directions:  Study the bar-graph given below & answer the questions.
Pie-chart given below shows the percentage distribution of total no. of boys in six different Schools.
Total Boys in all schools together = 6400

If number of boys in school A and school D together is 2/5 th of the total students in both schools then find difference of girls in school A and school D?

A unique circle can always be drawn through x number of given non-collinear points, then X must be