Quantitative Aptitude - Arithmetic Ability Questions

An army of 12000 consists of Europeans and Indians. The average height of a European is 5ft 10 inches and that of an Indian is 5ft 9 inches and that of the whole army is 5ft 9 3/4 inches. Then the number of Indians in the army is ?

If x - y = -6 and x + y = 16, then x2- y2 is?

Ticket for an adult is Rs 1500 and a child is Rs 800. 1 child goes free with two adults. If a group has 25 adults and 12 children what is the discount the group gets?

The average age of 120 members of a society is 60.7 years. By addition of 30 new members, the average age becomes 56.3 years. What is the average age (in years) of newly joined members?

Which of the fractions given below, when added to 5/8, gives 1?

On a certain principal if the Simple interest for two years is Rs 3000 and Compound interest for the two years is Rs 3225, what is the rate of Interest?

Vishnu travelled equal distances at speeds of 10 kmph, 30 kmph and 8 kmph and took a total of 15.5 min to complete. Find the total distance he travelled, in km.

P(4,2) and R(-2,0) are vertices of a rhombus PQRS. What is the equation of diagonal QS.