Question

Mr. Aravind has a total of Rs.15000. He spends 30 % of his money on education. How many rupees does he spend on his education?
(a) Rs.5000
(b) Rs.4500
(c) Rs.1000
(d) Rs.5500

Answer 1

Hint: We know that x % of any number ‘N’ is equal to \[\dfrac{x.N}{100}\]. Use this formula to calculate the money spent by Mr. Aravind on education which is 30 % of Rs.15000.

Complete step-by-step answer:
Here, we are given that Mr. Aravind has a total of Rs.15000. We have to find the value of the money he spends on his education if he spends 30 % of his money on education. Before proceeding with this question, let us understand the concept of percentage. In Mathematics, a percentage is a number or ratio that can be expressed as a fraction of 100, which means, a part per hundred. The word percentage means per 100. It is represented by the symbol “%”’. Percentages are dimensionless or unitless numbers. For example, if we say 50 % of a number, then it means 50 percent of its whole. Let us use this method to calculate the percentage of a number.
Suppose, we have a number ‘N’ and we have to calculate the x % of it, then we get,
x % of the number ‘N’ \[=\dfrac{x.N}{100}.....\left( i \right)\]
Now, let us consider our question. Here, Mr. Aravind has a total of Rs.15000. He spends 30 % of his money on education. So, we get,
Money spent by Mr. Aravind on education = 30 % of total money = 30 % of Rs.15000
We know that % of the number ‘N’ \[=\dfrac{x.N}{100}\]. By using this, we get,
Money spent by Mr. Aravind on education \[=\dfrac{30\times 15000}{100}\].
By simplifying RHS of the above equation, we get,
Money spent by Mr. Aravind on education = Rs.4500
Hence the money spent by Mr. Aravind on his education out of total Rs.15000 is Rs.4500.

Note: In this question, students often make the mistake of calculating the answer by using \[\dfrac{x}{N}\times 100\] which is wrong. They must note that x % of the number ‘N’ is \[\dfrac{x\times N}{100}\] a while if we want to find what percent of the number ‘N’ is number ‘x, then we use \[\dfrac{x}{N}\times 100\]. Students must remember and understand the concept of percentages properly because it has many applications in the practical world also and not just in theory.