how to calculate Qd=15.0-0.2P

To calculate the quantity demanded (Qd) using the equation Qd = 15.0 - 0.2P, you need to have the corresponding price (P) value. Once you have the price value, follow these steps:

1. Substitute the given price value into the equation for P.
2. Multiply the price value by 0.2.
3. Subtract the result from 15.0.
4. The resulting value is the calculated quantity demanded (Qd).

Here's an example calculation:

Given: P = $10
Qd = 15.0 - 0.2P

Substituting the given price:
Qd = 15.0 - 0.2(10)
Qd = 15.0 - 2
Qd = 13.0

Therefore, when the price is $10, the calculated quantity demanded is 13.0 units.