Let's break down the problem step by step to find the total number of notes Suresh has.

Step 1: Define the number of notes

Let the number of notes for each denomination (Rs. 1, Rs. 5, Rs. 10, Rs. 20, and Rs. 50) be $x$.

Step 2: Express the total amount in terms of $x$

The total amount Suresh has is Rs. 1290, which is the sum of the value of all notes. The value contributed by each denomination is:

$\text{Total Value} = 1 \times x + 5 \times x + 10 \times x + 20 \times x + 50 \times x$

Step 3: Simplify the expression

Factor out $x$ from the equation:

$\text{Total Value} = x \times (1 + 5 + 10 + 20 + 50)$

Calculate the sum inside the parentheses:

$\text{Total Value} = x \times 86$

So, we have:

$86x = 1290$

Step 4: Solve for $x$

Now, solve for $x$:

$x = \frac{1290}{86} = 15$

Step 5: Calculate the total number of notes

Since Suresh has $x$ notes of each denomination, and there are 5 different denominations, the total number of notes is:

$\text{Total number of notes} = 5 \times x = 5 \times 15 = 75$

So, Suresh has a total of 75 notes.

Would you like further details or have any questions? Here are some related questions:

1. What would be the total amount if Suresh had 20 notes of each denomination?
2. How many notes of Rs. 20 denomination does Suresh have?
3. What if the total amount was Rs. 1720 with the same denominations?
4. How would the total number of notes change if one denomination was missing?
5. What is the value of notes of Rs. 50 denomination alone?

Tip: When dealing with problems involving equal numbers of different denominations, setting up an equation by factoring out the common variable helps in solving the problem efficiently.