Mathematics (Simplification সরলীকরণ)

1) A product's price is increased by 15% and then decreased by 15%. What is the net effect on price?

2) If a value is successively increased by 30% and then decreased by 20%, what is the overall percentage change?

3) The population of a town decreases by 15% annually. If its present population is 20,000, what was it one year ago?

4) If the salary of A is 25% more than that of B, then B's salary is what percentage less than A's?

5) If 60% of a number is added to 60, the result is the number itself. What is the number?

6) If the price of an article is increased by 25%, then by what percentage should the new price be reduced to bring it back to the original price?

7) A population increases by 10% in the first year and decreases by 10% in the second year. What is the net percentage change in two years?

8) What is the value of (15 - 7) * 3 + 8 / 4?

9) If a person's salary is increased by 20% and then decreased by 20%, what is the net change in salary?

10) If the price of sugar increases by 20% and a family wants to keep their expenditure on sugar the same, by what percentage should they reduce their consumption?