A cylindrical capsule has hemispherical ends of the radii equal to radius of the cylindrical part. If length of the capsule is 40 m and radius 6 m, what is the total surface area of this capsule?
The average marks of 10 students in an examination was 25. It was later found that the marks of one student had been wrongly entered as 34 instead of 43. What is the correct average?
A man walks 5 kilometre towards South and then turns to the right. After walking 3 kilometre, he turns to the left and walks 5 kilometre. Now in which direction is he from the starting point?
The ages of A and B differ by 16 years. If 6 years ago, the elder one was 3 times as old as the younger one, find the present age of the younger between A and B?
A mixture contains acid and water in the ratio of 7 : 3. If 4 litres of water is added to it, then the ratio of acid and water becomes 7 : 4. What is the quantity (in litres) of acid in the mixture?