Quantitative Aptitude - Arithmetic Ability Questions

Two smaller circles touch a large circle internally and pass through the center O of the larger circle. If the diameter of the bigger circle is 28 cm, thenwhat is the area of the bigger circle which is not enclosed by the two smaller circles (in sq.cm)?

ΔABC is right angled at B. BD is an altitude. AD = 3 cm and DC = 9 cm. What is the value of AB (in cm)?

To cover a distance of 144 km in 3.2 hours what should be the average speed of the car in meters/second?

If the average age of four children is 12 years and the average age of these children and their fathers is 20 years, what is the age of the father?

Find the mean proportional between 2 and 98?

If Tan A = 15/8 and Tan B = 7/24, then Cos(A - B) = ?

In the following question, select the missing number from the given series.
 
1912, 2012, 2133, 2277, 2446, ?

What is the value of (tan45° + 1/√2) ?