Quantitative Aptitude - Arithmetic Ability Questions

A dealer marks his goods 20% above cost price. He then allows some discount on it and makes a profit of 8%. The rate of discount is

D and E are points on side AB and AC of ΔABC. DE is parallel to BC. If AD:DB = 1:4 and area of ΔADE is 6 sq cm, what is the ratio of area of ΔADE: area of quadrilateral BDEC?

A solid sphere of radius 6 cm is melted and re-casted into a hollow cylinder of uniform thickness. If the external radius of the base of the cylinder is 5 cm and its height is 32 cm, find the uniform thickness of the cylinder ?

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?

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observations is

If 177 is divided into 3 parts in the ratio 1/2 : 2/3: 4/5, then the second part is

A truck covers a distance of 550 metres in one minute where as a bus covers a distance of 33 km in 3/4 hours. Then the ratio of their speeds is :

ax + 3y = 6 has slope -2/3. What is the value of a?