Quantitative Aptitude - Arithmetic Ability Questions

21% of 500 + 31% of 1100 - 30% of 790 = ? 

In an election between two candidates, the winning candidate has got 70% of the votes polled and has won by 15400 votes. What is the number of votes polled for loosing candidate?

When a number is divided by 138 the remainder is 26. What will be the remainder if the same number is divided by 23 ?

If a/(a+b) = 15/21, what is (a+b)/(a-b) is equal to?

In an army selection process, the ratio of selected to unselected candidates was 6:1. If 30 less had applied and 10 less selected, the ratio of selected to unselected would have been 7:1. How many candidates had applied for the process?

A plane is going in circles around an airport. The plane takes 3 minutes to complete one round. The angle of elevation of the plane from a point P on the ground at time t seconds is equal to that at time (t + 30) seconds. At time (t + x) seconds, the plane flies vertically above the point P. What is x equal to?

In a class of 80 students and 5 teachers, each student got shopping coupons that are 15% of the total number of students and each teacher got shopping coupons, that are 25% of the total number of students. How many shopping coupons were there?

A slice from a circular pizza of diameter 14 inches is cut in asuch a way that each slice of pizza has a central angle of 45°. What is the area of each slice of Pizza(in square inches)?