Quantitative Aptitude - Arithmetic Ability Questions

The selling price of an article is 8/5th of its cost price. Then the gain percentage is

If 40 is 0.05% of x, then what is the value of x?

If cot 60° + cosec 60° = x, then the value of x is

A tetrahedron has 4 vertices. How many edges does it have?

In a mixture, water and milk are in the ratio of 3 : 5. In the second mixture, the ratio of water and milk is 9 : 11. If these two mixtures be mixed to form anew mixture in which water and milk are in ratio 5 : 7, then what is the ratio of these two mixtures in the new mixture?

A circle and a square have same area. The ratio of the side of the square to the radius of the circle will be:

For an article the profit is 170% of the cost price. If the cost price increases by 20% but the selling price remains same, then what is the new profit percentage?

A, B and C can finish a job working alone in 20, 30 and 60 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to finish the remaining part of the job?