Quantitative Aptitude - Arithmetic Ability Questions

When a number is increased by 21, it becomes 114% of itself. What is the number?

When a number is increased by 28, it becomes 107% of itself. What is the number?

If 7x + 6y = 5xy and 10x ­- 4y = 4xy, then value of x and y is

If a retailer offers a discount of 32% on the marked price of his goods and thus ends up selling at cost price, what was the % markup price?

56% of 250 is

The sum of two positive integers is 80 & difference between them is 20. Then what is difference of squares of those numbers ?

In the following question, four groups of three numbers are given. In each group the second and third number are related to the first number by a Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

2cos[(C+D)/2]sin[(C-D)/2] is equal to