Manoj has 26 notes of two rupees and some five rupees notes. If he has Rs. 127, then how many five rupees notes does he have?
(a) 12
(b) 20
(c) 13
(d) 15

Hint: We start solving the problem by assigning the variable for total number of five rupees notes that Manoj has as ‘x’. So, the total amount would be 5x. We then write the equation that represents the sum of all the notes present using the variable for the total number of five rupees notes. We then make necessary calculations to find the required value of the total number of five rupees notes.

Complete step by step answer:
According to the problem, we are given that Manoj has 26 notes of two rupee and some five rupees notes. We need to find the number of five rupees notes he has if he has a total of Rs. 127.
Let us assume the total number of five rupees notes that Manoj has, is ‘x’.
So, we will have 26 two rupees notes and ‘x’ five rupees notes which constitute Rs. 127.
Now, let us write the equation that represents the given information.
So, we get $\left( 26\times 2 \right)+\left( x\times 5 \right)=127$.
$\Rightarrow 52+5x=127$.
$\Rightarrow 5x=127-52$.
$\Rightarrow 5x=75$.
$\Rightarrow x=\dfrac{75}{5}$.
$\Rightarrow x=15$.
So, we have found that Manoj has 15 five rupees notes.

So, the correct answer is “Option d”.

Note: We should do each step carefully to avoid mistakes while solving this problem. Whenever we get this type of problem, we should start solving by assuming a variable for unknowns to avoid confusions and mistakes. We can also find the percentage of two rupee and five rupees notes present in the total sum given. Similarly, we expect the problem to find the total number of ten rupees notes will give the result if 12 five rupees notes are removed after finding the value of ‘x’.