Quantitative Aptitude - Arithmetic Ability Questions

The average age of a class of 6 girls is x years. Four new girls having ages x – 2, x + 2, x + 4 and x + 6 joins the class. What is the new average age (in years) of the class?

What approximate value should come in place of the question mark (?) in the following questions? (You are not expected to calculate the exact value.)

21.003 × 39.998 –209.91 = 126× ?

The value of 2 Tan53°Cot37°-Cot80°Tan10° ?

In a triangle the length of the side opposite the right angle is 9√3 cm, what is the length of the side opposite to the angle which measures 30 degree?

Of the 3 numbers whose average is 22, the first is 3/8th the sum of other 2. What is the first number?

∆XYZ is right angled at Y. If tanX = 24/7, then what is the value of cotZ ?

Point A divides segment BC in the ratio 1:3. Co-ordinates of B are (4,-4) and C are (0,6). What are the co-ordinates of point A?

Identical cubes of largest possible size are cut from a solid cuboid of size 65 cm × 26 cm × 3.9 cm. What is the total surface area (in cm2) of all the small cubes taken together?