Quantitative Aptitude - Arithmetic Ability Questions

If 3x + 4y – 2z + 9 = 17, 7x + 2y + 11z + 8 = 23 and 5x + 9y + 6z – 4 = 18, then what is the value of x + y + z – 34?

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 ?

The average revenues of 9 consecutive years of a company is Rs 80 lakhs. If the average of first 5 years is Rs 75 lakhs and that of last 5 years is Rs 87 lakhs, find the revenue for the 5th year.

If the present ages of a father and his son are 48 years and 28.8 years old respectively, then the father can say to his son, "I was ......... of your present age when you were born".

Nine years later, age of B will be equal to the present age of A. Sum of A's age 3 years later and B's age 4 years ago is 76. If C is half of the present age of B, then what will be C's age (in years) after 10 years?

Among three numbers, the first is twice the second and thrice the third. If the average of three numbers is 506, then what is the difference between the first and the third number?

The product of the ages of Swati and Aparna is 120. If thrice the age of Aparna is more than Swati's age by 2 years, find the age of Swati.

If the average age of 20 students in Class-I is 10 years and average age of 25 students in Class II is 12 years, find the average age (in years) of all students.