Quantitative Aptitude - Arithmetic Ability Questions

In a class, there were 9 boys and some girls. In a test the mean score obtained by the boys was 12 while that obtained by the girls was 14. If the overall average was 13.1, what was the total number of students in the calss?

Cost price of 28 articles is equal to Sale price of 21 articles, then percentage of profit is

If α and β are roots of the equation 3x2 – 13x + 14 = 0, then what is the value of (α/β) + (β/α)?

At what point does the line 4x - 3y = -6 intercept the y-axis?

What is the value of (cos 40° – cos 140°)/(sin 80° + sin 20°)?

Square of (7 ­- 4x) is

If a3 + b3 = 19 and ab = -6 , then what is the value of a + b?

At 30% discount the selling price of an article is Rs 1050. What is the selling price (in Rs) if the discount is 15%?