Quantitative Aptitude - Arithmetic Ability Questions

If x + y = 10 and xy = 4, then what is the value of x4 + y4?

The length and breadth of a rectangle are 24 cm and 7 cm respectively. What must be the length of its diagonal (in cm)?

In a class of 50 students there are 27 boys. The average weight of these boys is 72 Kg and average weight of the full class is 55.44 kgs. What is the average weight (in kgs) of the girls of the class?

In a class of 55 students there are 34 girls. The average weight of these girls is 51 Kg and average weight of the full class is 55.2 kgs. What is the average weight of the boys of the class?

Product of digits of a 2-digit number is 15. If we add 18 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.

If curved surface area of a cylinder is 1386 sq cm and height is 21 cm, what will be its radius? (Take π = 22/7)

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

The mean of 20 observations is 19. One more observation is included and the new mean becomes 20. The 21st observation is