ILL GIVE BRANLIEST AND MANY POINTS

Percent change formula:

C = x    -   x

        2         1 / x

                            1

To calculate percent change we need to take the difference between the starting value and final value, divide by the absolute value of the starting value, and multiply the result by 100.

1. 72 is a 33.333% decrease of 108. Round is 33%.

2. 90 is a 20% increase of 75. Round is 20%.

3. 49 is a 75% increase of 28. Round is 80%.

The total cost is .

Step-by-step explanation:

Given: Original price of calculator is , discount is and the sales tax is .

To find: The total cost

Solution:

We have,

Original price of calculator

Discount

Sales tax

Now, first we need to find the cost after applying the discount.

So, discount

Therefore, the cost after applying the discount

Now, we have to find the sales tax. Therefore,

Sales tax

So, the total cost is .

Hence, the total cost is .