Quantitative Aptitude - Arithmetic Ability Questions

X, Y and Z can do a piece of work in 30,40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?

If Cot θ = 21/20, then what is the value of Sec θ?

In an army selection process, the ratio of selected to unselected candidates was 9:2. If 80 less had applied and 20 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?

In how many months will Rs 8,000 yield Rs 2,648 as compound interest at 20% per annum compounded semi-annually?

2 litre of pure alcohol is added to 6 litre, 40% alcohol solution. The percentage of water in the solution is _____ .

At 10% discount the selling price of a toaster is Rs 18000, what is the selling price if the discount is 37.5%?

Find the radius of the circle if the area of its sector is 30.8 sq cm whose corresponding central angle is 72°?

If A = 400 and B = 600, then A is how much percentage less than B?