Quantitative Aptitude - Arithmetic Ability Questions

The sum of present age of father and his son is 60 yrs. Six years ago, father's age was five times the age of the son. After 6 years, son's age will be?

A man starts walking from a place X and reaches the place Y in 12 hours. He travels 3/7th of the total distance at the speed of 3 km/hr and the remaining distance at the speed of 4 km/hr. What is the distance (in km) between X and Y?

The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is

If 3+12=x+3y, then the x+y is 

If 2x - 5y = 5 and 2x - y = 9, then x - y is ______.

The ratio of two numbers is 5 : 4. If the sum of both the numbers is 180, then what is the smaller number among both the numbers?

What is the value of sec2θ + 1sec2θ - 1 x 12cotθ - tanθ ?

If a3 + 3a2 + 9a = 1, then what is the value of a3 + (3/a)?