A number is decreased by 10% and the resulting number is again decreased by 20%. What is the final percentage of decrease?
28%
To find the final percentage decrease, we need to calculate the result of successive percentage decreases step by step.
Let's assume the initial value of the number is \( x \).
First Decrease:
The number is decreased by 10%. The result after the first decrease is:
\( x - \frac{10}{100} \times x = x \times (1 - 0.10) = 0.9x \)
Second Decrease:
The resulting number is decreased by 20%. Now apply 20% decrease on \( 0.9x \):
\( 0.9x - \frac{20}{100} \times 0.9x = 0.9x \times (1 - 0.20) = 0.72x \)
Final Calculation:
The final value is \( 0.72x \). The initial value was \( x \). The decrease from the original number is:
\( x - 0.72x = 0.28x \)
The percentage decrease from the original number is:
\(\frac{0.28x}{x} \times 100 = 28\% \)
Therefore, the final percentage decrease is 28%.
Similar Questions
In a motor of 120 machine parts, 5% parts were defective. In another motor of 80 machine parts, 10% parts were defective. For the two motors considered together, the percentage of defective machine parts were:
A school has 8 periods of 45 minutes each, every day. How long will each period be if the school has to have 9 periods everyday, assuming the working hours to be the same?
A basket contains 300 mangoes. 75 mangoes were distributed among some students. Find the percentage of mangoes left in the basket.
The weights of two iron balls are 3.5 kg and 7.5 kg. What is the percentage weight of the 1st ball with respect to the 2nd ball?
If 35% of A's income is equal to 25% of B's income, then the ratio of A's income to B's income is
A man spends 15% of his income. If his expenditure is Rs. 75, his income (in rupees) is:
The price of rice has increased by 60%. In order to restore the original price, the new price must be reduced by
If "basis points" are defined so that 1 percent is equal to 100 basis points, then how many basis points is 82.5 percent greater than 62.5 percent?
In the last financial year, a car company sold 41,800 cars. In this year, the target is to sell 51,300 cars. By what percent must the sale be increased?
Numbers of boys and girls are 'x' and 'y' respectively; ages of a girl and a boy are 'a' years and 'b' years respectively. The average age (in years) of all boys and girls is:
Important Questions from Percentage
In an examination, 25% of the candidates failed in Mathematics and 12% failed in English. If 10% of the candidates failed in both the subjects and 292 candidates passed in both the subjects, which one of the following is the number of total candidates appeared in the examination?
What is the value of 9% of 5500 + 2.4% of 1100 - 40% of 1600?
Population of a village is 7960 in which 4660 are female. If in that village 60% are literate in which 70% female are literate, then what is the number of literate male ?
The numbers of students of three classes of a school are in the ratio 4 : 5 : 6. If numbers of students in these classes increase by 25%, 20% and 25% respectively, then ratio of numbers of students will become:
In an examination, Ram obtained 20 % more than Ashok but 10% less than Rajesh. If the marks obtained by Ashok is 1080. Then the Percentage marks obtained by Rajesh if the full marks is 2000 ;
