QUESTION

# How many pencils can we purchase with 20 rupees if one pencil costs 2 rupees?

For example, the cost of 2 mangoes is rupees 10 then, the cost of one mango will be $\dfrac{10}{2}=5$rupees. Now, we can find the cost of ‘$n$’ mangoes as $(5\times n)$. Similarly, we have total cost to spend as rupees 20, and the cost of 1 pencil is rupees 2. So, the number of pencils that we can purchase in rupees 20 is given by – total amount of money ÷ cost of 1 pencil.
$=\dfrac{Rs.20}{Rs.2}$
$=10$ Pencils.
Note: When every type of question arises it is preferred to find the value of ‘$n$’ unit because, if we know the value of 1 unit then we can directly find the ‘$n$’ unit. So, always try to find the value of 1 unit in this type of question and apply a unitary method.