Quantitative Aptitude - Arithmetic Ability Questions

If selling price of 39 articles is equal to the cost price of 42 articles, then what will be the profit percentage?

A thief is stopped by a policeman from a distance of 350 metres. When the policeman starts the chase, the thief also starts running. Assuming the speed of the thief as 5 km/h and that of the policeman as 7 km/h, how far the thief would have run, before he is over- taken?

The sum of the digits of a 2-digit number is 11. If we add 45 to the number, the new number obtained is a number formed by interchange of the digits. What is the number?

In a class of 60 students there are 30 girls. The average weight of these girls is 58 Kg and average weight of the full class is 63 kgs. What is the average weight of the boys of the class?

20 pens and 46 pencils were purchased for Rs. 235. If the average price of a pencil is Rs. 2.50 then calculate the average price (in Rs.) of a pen.

Rs. 750 invested for 3 months gave an interest of Rs. 18. What was the simple rate of interest per annum?

What is the HCF (highest common factor) of 57 and 513?

If θ is positive acute angle and 4sin2θ = 3, then the value of tan θ - cot θ/2 is