To calculate the amount of markup on each watch, we can use the following formula:

$\text{Markup} = \text{Selling Price} - \text{Cost Price}$

However, we are given the markup rate and the selling price, so we need to find the cost price first. The markup rate is 150%, which means the selling price is 250% of the cost price (100% of the cost plus 150% markup).

Let's denote the cost price by $C$. Then, the selling price can be expressed as:

$\text{Selling Price} = C \times \left(1 + \frac{150}{100}\right) = C \times 2.5$

Given that the selling price is $435, we can set up the equation:

$435 = C \times 2.5$

Now, solve for $C$:

$C = \frac{435}{2.5} = 174$

Now that we have the cost price, the markup can be calculated as:

$\text{Markup} = \text{Selling Price} - \text{Cost Price} = 435 - 174 = 261$

So, the amount of markup on each watch is $261.

Would you like more details or have any questions about this solution? Here are some related questions:

1. What is the cost price of a different item if it has a markup of 200% and a selling price of $600?
2. How would the markup change if the markup rate was reduced to 100%?
3. If the store wants to increase the selling price by $50, what would the new markup amount be?
4. What would be the selling price if the markup rate was increased to 175%?
5. How would a 10% discount on the selling price affect the markup amount?

Tip: When calculating markup, remember that the markup rate is always based on the cost price, not the selling price.