Calculating the percentage is one of the basic and important operations in mathematics. Percentage means per hundred. The symbol used for percentage is given by ‘%’. The whole quantity of any substance is the hundred percent (100%) of the whole substance. The fifty percent (50%) of the substance is half of the whole quantity. Similarly twenty five percent (25%) of the substance is one fourth of the whole quantity. Therefore the percentage signifies the portion of the given substance or quantity. A percentage can be converted to a fraction and vice-versa.
Example 1: Sam has 64 red and green pencils. If he has 16 red pencils find the percentage of green pencils he has?
Solution: The total number of the pencils Sam has = 64.
Number of red pencils = 16. (The remaining will be green)
Hence number of green pencils = 64 – 16 = 48.
The percent or the green pencils = number of green pencils/ Total number x 100.
The percent of green pencils = 48 /60 * 100 = 480/6 = 60 %.
Hence 60% of the pencils Sam has are green.
Question: Multiple choice question (Pick the correct option.)
What is the 20% of 720?
a) 720 b) 20 c) 144 d) None of these.
Correct answer: option c.
The given number = 720.
The percentage of the number to be found = 20%.
The 20% can be written as 20/100.
The 20% of 720 further gives: 720 x 20/100 = 720/5 = 144.
Hence the answer is = 144.