Aptitude : Percentage

(21) A man’s salary is reduced by 20%. By what percent should his reduced salary be increased to bring it back to his original salary?

• (a)25 Percentage
• (b)15 Percentage
• (c)18 Percentage
• (d)20 Percentage

Answer

Correct Answer : (a) 25 Percentage
Original salary = $100
Salary reduction = 20%
New salary = $100 – 20% of $100 = $80
Increase needed to bring salary back to $100 = $20
Percentage increase = $20/$80 = 25%

(22) If 30% of a certain number is 12.6, what is 40% of that number?

• (a)18 Percentage
• (b)19 Percentage
• (c)20.25 Percentage
• (d)16.8 Percentage

Answer

Correct Answer : (d) 16.8 Percentage
Let’s assume the certain number is “X”.
We are given that 30% of X is equal to 12.6. Mathematically, this can be represented as:
0.30 * X = 12.6
To find 40% of the number, we can calculate:
0.40 * X = (0.40/0.30) * (0.30 * X)
Since we know that 0.30 * X is equal to 12.6, we can substitute this value into the equation:
0.40 * X = (0.40/0.30) * 12.6
Simplifying this:
0.40 * X = (4/3) * 12.6
0.40 * X = (4/3) * 12.6
0.40 * X = 4.2 * 4
0.40 * X = 16.8
Therefore, 40% of the certain number is 16.8.

(23) If 70% of a number is 630, what is the number?

• (a)180 Percentage
• (b)600 Percentage
• (c)900 Percentage
• (d)800 Percentage

Answer

Correct Answer : (c) 900 Percentage
Let’s assume the number is “X”.
We are given that 70% of X is equal to 630. Mathematically, this can be represented as:
0.70 * X = 630
To find the value of X, we can solve this equation:
X = 630 / 0.70
X = 900
Therefore, the number is 900.

(24) The price of an article was cut by 10% to restore to its original price, the new price must be increased by what percent?

• (a)12 Percentage
• (b)13.25 Percentage
• (c)11.11 Percentage
• (d)12.25 Percentage

Answer

Correct Answer : (c) 11.11 Percentage
Let x be the original price of the article. After a 10% cut, the new price is 0.9x. To restore the price to x, the new price must be increased by 0.1x/0.9x = 11.11%.
Therefore, the new price must be increased by 11.11% to restore it to the original price.
Original price = x
New price after 10% cut = 0.9x
Increase needed to restore price to x = 0.1x
Percentage increase = 0.1x/0.9x = 11.11%

(25) If 25% of a number is subtracted from the number, the result is 75. Find the number.

• (a)150
• (b)100
• (c)220
• (d)210

Answer

Correct Answer : (b) 100
Let x be the number.
25% of x = x/4
x – x/4 = 75
3x/4 = 75
x = 100
Therefore, the number is 100.