Quantitative Aptitude - Arithmetic Ability Questions

Three bottles of equal capacity have mixture of milk and water in ratio 5 : 7, 7 : 9 and 2 : 1 respectively. These three bottles are emptied into a large bottle. What is the percentage of milk in the new mixture?

A boat moves down stream at the rate of 8km/hr. and upstream at 4Km/hr. The speed of the boat in still waters is:

ABC is a triangle. AB = 5 cm, AC = √41 cm and BC = 8 cm. AD is perpendicular to BC. What is the area (in cm2) of triangle ABD?

Working together A and B can do a job in 40 days, B and C in 36 days and all three together in 24 days. In how many days can B alone do the job?

A can paint a house in 55 days and B can do it in 66 days. Along with C, they did the job in 12 days only. Then, C alone can do the job in how many days?

If the radius of a circle is decreased to 25% of its original value, calculate the percentage decrease in the area of the circle

The area of the largest sphere ( in cm2) that can be drawn inside a square of side 18 cm is

Tanzeem spent 1/5 of his salary on his friends, 1/10 of his salary on accommodation and 1/4 of his salary on savings. If he has Rs. 1800 left in his wallet,then find his total expenditure on accommodation and savings.