Quantitative Aptitude - Arithmetic Ability Questions

If cot A = n/(n + 1) and cot B = 1/(2n + 1), then what is the value of cot (A + B)?

Find 150% of X, if X is the least number which when divided by 6, 7, 8, 9 and 12 leaves remainders 2, 3, 4, 5 and 8 respectively.

Let A(O,-1), B(0,3) and C(2,1) be three points. Let   △1 be the area of the triangle ABC and △2 be the area of the triangle formed by the mid points of the sides of the triangle whose vertices are A, B and C such that △1=1 ,△2=x Find the value of x .

A car travelling at an average speed of 72 km/hr takes 9 minutes to travel a certain distance. By how much should it increase its speed (in km/hr) to travel the same distance in 8 minutes?

Selling price of an article is Rs 1144. If loss percentage is 12%, then what is the cost price (in Rs) of article?

In a class, average height of all students is 'a' cms. Among them, average height of 10 students is 'b' cms and the average height of the remaining students is 'c' cms. Find the number of students in the class. (Here a>c and b>c )

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?

A person lent certain sum of money at 10% per annum simple interest. In 20 years the interest amounted to Rs 500 more than the sum lent. What was the sum lent (in Rs)?