Quantitative Aptitude - Arithmetic Ability Questions

12 copies of a book were sold for Rs. 1800 thereby gaining cost price of 3 copies. The cost price of a copy of the book is

If the cost price of 25 pens is equal to the selling price of 20 pens, then the profit percent is

What is the third proportional to 9 and 45?

In two types of brass, the ratios of Copper to Zinc are 8:3 and 15:7 respectively. If the two types of brass be melted and mixed in the ratio 5:2 a new type of brass is obtained. The ratio of Copper to Zinc in this new type of brass is

A fraction is greater than its reciprocal by 9/20. What is the fraction?

The maximum value of 5+20x-4x2, when X is real number

If x + y + z = 22 and xy + yz + zx = 35, then what is the value of (x – y)2 + (y – z)2 + (z – x)2?

3/5 of my current age is the same as 5/6 of that of one of my cousin. My age ten ago will be his age four years hence. My current age is ___ years.