Question

A student divided a number by two when he was required to multiply it by 2. The answer he got was 2. The correct answer should have been
A. 8
B. 12
C. 6
D. 4

Answer 1

Hint: Variable method is a method in which we denote the unknown number with an alphabet and then treat that alphabet as a number. Use the given data and write a linear equation in x and then find the value of x. Then find the actual correct answer.

Complete step by step solution:
In the given question it is said that a student had to multiply a number by 2 but instead he divided that number by 2 and the answer that he got was 2. Now, we are supposed to find the actual correct answer. For this, let us first find the number which is being multiplied by 2.We shall find the number by using a variable method. Variable method is a method in which we denote the unknown number with an alphabet and then treat that alphabet as a number.

Let the unknown number whose value we have to find be x. This means that we have to find the value of x. We can do this with the given information. It is said that the student divided the number ‘x’ by 2 and got an answer of 2. This means that $\dfrac{x}{2}=2$.From the above equation we can write that $x=2\times 2=4$. Therefore, the number that is being multiplied or divided by 2 is 4. It is said that the boy had to multiply 4 by 2. We know that when we multiply 4 by 2, we get an answer of 8.Therefore, the correct answer is 8.

Hence, the correct option is A.

Note:Be careful while the linear equation in x. Students may accidently write the equation as $\dfrac{2}{x}=2$It is given that when we divide the number ‘x’ by 2, we get an answer of 2 and not 2 divided by the number ‘x’ results 2.